Altitude sickness

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Altitude_sickness 

 

Altitude sickness
Other names	High-altitude sickness, altitude illness, hypobaropathy, altitude bends, soroche
Altitude sickness warning – Indian Army
Specialty	Emergency medicine
Symptoms	Headache, vomiting, feeling tired, trouble sleeping, dizziness
Complications	High-altitude pulmonary edema (HAPE), high-altitude cerebral edema (HACE)
Usual onset	Within 24 hours
Types	Acute mountain sickness, high-altitude pulmonary edema, high-altitude cerebral edema, chronic mountain sickness
Causes	Low amounts of oxygen at high elevation
Risk factors	Prior episode, high degree of activity, rapid increase in elevation
Diagnostic method	Based on symptoms
Differential diagnosis	Exhaustion, viral infection, hangover, dehydration, carbon monoxide poisoning
Prevention	Gradual ascent
Treatment	Descent to lower altitude, sufficient fluids
Medication	Ibuprofen, acetazolamide, dexamethasone, oxygen therapy
Frequency	20% at 2,500 metres (8,000 ft) 40% at 3,000 metres (10,000 ft)

Altitude sickness, the mildest form being acute mountain sickness (AMS), is the harmful effect of high altitude, caused by rapid exposure to low amounts of oxygen at high elevation. People can respond to high altitude in different ways. Symptoms may include headaches, vomiting, tiredness, confusion, trouble sleeping, and dizziness. Acute mountain sickness can progress to high-altitude pulmonary edema (HAPE) with associated shortness of breath or high-altitude cerebral edema (HACE) with associated confusion. Chronic mountain sickness may occur after long-term exposure to high altitude.

Altitude sickness typically occurs only above 2,500 metres (8,000 ft), though some are affected at lower altitudes. Risk factors include a prior episode of altitude sickness, a high degree of activity, and a rapid increase in elevation. Diagnosis is based on symptoms and is supported in those who have more than a minor reduction in activities. It is recommended that at high altitude any symptoms of headache, nausea, shortness of breath, or vomiting be assumed to be altitude sickness.

Prevention is by gradually increasing elevation by no more than 300 metres (1,000 ft) per day. Being physically fit does not decrease the risk. Treatment is generally by descending and sufficient fluids. Mild cases may be helped by ibuprofen, acetazolamide, or dexamethasone. Severe cases may benefit from oxygen therapy and a portable hyperbaric bag may be used if descent is not possible. Treatment efforts, however, have not been well studied.

AMS occurs in about 20% of people after rapidly going to 2,500 metres (8,000 ft) and 40% of people going to 3,000 metres (10,000 ft). While AMS and HACE occurs equally frequently in males and females, HAPE occurs more often in males. The earliest description of altitude sickness is attributed to a Chinese text from around 30 BCE which describes "Big Headache Mountains", possibly referring to the Karakoram Mountains around Kilik Pass.

Signs and symptoms

Left: A woman at normal altitude. Right: The same woman with a swollen face while trekking at high altitude (Annapurna Base Camp, Nepal; 4130 m).

People have different susceptibilities to altitude sickness; for some otherwise healthy people, acute altitude sickness can begin to appear at around 2,000 metres (6,600 ft) above sea level, such as at many mountain ski resorts, equivalent to a pressure of 80 kilopascals (0.79 atm). This is the most frequent type of altitude sickness encountered. Symptoms often manifest within ten hours of ascent and generally subside within two days, though they occasionally develop into the more serious conditions. Symptoms include headache, confusion, fatigue, stomach illness, dizziness, and sleep disturbance. Exertion may aggravate the symptoms.

Those individuals with the lowest initial partial pressure of end-tidal pCO₂ (the lowest concentration of carbon dioxide at the end of the respiratory cycle, a measure of a higher alveolar ventilation) and corresponding high oxygen saturation levels tend to have a lower incidence of acute mountain sickness than those with high end-tidal pCO₂ and low oxygen saturation levels.

Primary symptoms

Headaches are the primary symptom used to diagnose altitude sickness, although a headache is also a symptom of dehydration. A headache occurring at an altitude above 2,400 metres (7,900 ft) – a pressure of 76 kilopascals (0.75 atm) – combined with any one or more of the following symptoms, may indicate altitude sickness:

Disordered system	Symptoms
Gastrointestinal	Loss of appetite, nausea, vomiting, excessive flatulation
Nervous	Fatigue or weakness, headache with or without dizziness or lightheadedness, insomnia, "pins and needles" sensation
Locomotory	Peripheral edema (swelling of hands, feet, and face)
Respiratory	Nose bleeding, shortness of breath upon exertion
Cardiovascular	Persistent rapid pulse
Other	General malaise

Severe symptoms

Symptoms that may indicate life-threatening altitude sickness include:

Pulmonary edema (fluid in the lungs)

Symptoms similar to bronchitis

Persistent dry cough

Fever

Shortness of breath even when resting

Cerebral edema (swelling of the brain)

Headache that does not respond to analgesics

Unsteady gait

Gradual loss of consciousness

Increased nausea and vomiting

Retinal hemorrhage

The most serious symptoms of altitude sickness arise from edema (fluid accumulation in the tissues of the body). At very high altitude, humans can get either high-altitude pulmonary edema (HAPE), or high-altitude cerebral edema (HACE). The physiological cause of altitude-induced edema is not conclusively established. It is currently believed, however, that HACE is caused by local vasodilation of cerebral blood vessels in response to hypoxia, resulting in greater blood flow and, consequently, greater capillary pressures. On the other hand, HAPE may be due to general vasoconstriction in the pulmonary circulation (normally a response to regional ventilation-perfusion mismatches) which, with constant or increased cardiac output, also leads to increases in capillary pressures. For those with HACE, dexamethasone may provide temporary relief from symptoms in order to keep descending under their own power.

HAPE can progress rapidly and is often fatal. Symptoms include fatigue, severe dyspnea at rest, and cough that is initially dry but may progress to produce pink, frothy sputum. Descent to lower altitudes alleviates the symptoms of HAPE.

HACE is a life-threatening condition that can lead to coma or death. Symptoms include headache, fatigue, visual impairment, bladder dysfunction, bowel dysfunction, loss of coordination, paralysis on one side of the body, and confusion. Descent to lower altitudes may save those affected by HACE.

Cause

See also: Breathing § Breathing at altitude, and Effects of high altitude on humans

 

Climbers on Mount Everest often experience altitude sickness.

Altitude sickness can first occur at 1,500 metres, with the effects becoming severe at extreme altitudes (greater than 5,500 metres). Only brief trips above 6,000 metres are possible and supplemental oxygen is needed to avert sickness.

As altitude increases, the available amount of oxygen to sustain mental and physical alertness decreases with the overall air pressure, though the relative percentage of oxygen in air, at about 21%, remains practically unchanged up to 21,000 metres (70,000 ft). The RMS velocities of diatomic nitrogen and oxygen are very similar and thus no change occurs in the ratio of oxygen to nitrogen until stratospheric heights.

Dehydration due to the higher rate of water vapor lost from the lungs at higher altitudes may contribute to the symptoms of altitude sickness.

The rate of ascent, altitude attained, amount of physical activity at high altitude, as well as individual susceptibility, are contributing factors to the onset and severity of high-altitude illness.

Altitude sickness usually occurs following a rapid ascent and can usually be prevented by ascending slowly. In most of these cases, the symptoms are temporary and usually abate as altitude acclimatization occurs. However, in extreme cases, altitude sickness can be fatal.

High altitude illness can be classified according to the altitude: high (1500-3500m), very high (3500-5500m) and extreme (above 5500m).

High altitude

At high altitude, 1,500 to 3,500 metres (4,900 to 11,500 ft), the onset of physiological effects of diminished inspiratory oxygen pressure (PiO₂) includes decreased exercise performance and increased ventilation (lower arterial partial pressure of carbon dioxide: PCO₂). While arterial oxygen transport may be only slightly impaired the arterial oxygen saturation (SaO₂) generally stays above 90%. Altitude sickness is common between 2,400 and 4,000 m because of the large number of people who ascend rapidly to these altitudes.

Very high altitude

At very high altitude, 3,500 to 5,500 metres (11,500 to 18,000 ft), maximum SaO₂ falls below 90% as the arterial PO₂ falls below 60mmHg. Extreme hypoxemia may occur during exercise, during sleep, and in the presence of high altitude pulmonary edema or other acute lung conditions. Severe altitude illness occurs most commonly in this range.

Extreme altitude

Above 5,500 metres (18,000 ft), marked hypoxemia, hypocapnia, and alkalosis are characteristic of extreme altitudes. Progressive deterioration of physiologic function eventually outstrips acclimatization. As a result, no permanent human habitation occurs above 6,000 metres (20,000 ft). A period of acclimatization is necessary when ascending to extreme altitude; abrupt ascent without supplemental oxygen for other than brief exposures invites severe altitude sickness.

Mechanism

The physiology of altitude sickness centres around the alveolar gas equation; the atmospheric pressure is low, but there is still 20.9% oxygen. Water vapour still occupies the same pressure too—this means that there is less oxygen pressure available in the lungs and blood. Compare these two equations comparing the amount of oxygen in blood at altitude:

	At Sea Level	At 8400 m (The Balcony of Everest)	Formula
Pressure of oxygen in the alveolus	${\textstyle 21\%\times (101.3{\text{ kPa}}-6.3{\text{ kPa}})-\left({\frac {5.3{\text{ kPa}}}{0.8}}\right)=13.3{\text{ kPa O}}_{2}}$	${\textstyle 21\%\times (36.3{\text{ kPa}}-6.3{\text{ kPa}})-\left({\frac {1.8{\text{ kPa}}}{0.74}}\right)=3.9{\text{ kPa O}}_{2}}$	${\textstyle F_{I}{\text{O}}_{2}\times (P_{\text{B}}-P_{{\text{H}}_{2}{\text{O}}})-\left({\frac {P_{{\text{CO}}_{2}}}{\text{RQ}}}\right)}$
Oxygen Carriage in the blood	${\textstyle \left(0.98\times 1.34\times 14{\frac {\text{g}}{\text{dL}}}\right)+(0.023\times 12{\text{ kPa}})={\frac {17.3{\text{ mL O}}_{2}}{100{\text{ mL blood}}}}}$	${\textstyle \left(0.54\times 1.34\times 19.3{\frac {\text{g}}{\text{dL}}}\right)+(0.023\times 3.3{\text{ kPa}})={\frac {14.0{\text{ mL O}}_{2}}{100{\text{ mL blood}}}}}$	${\textstyle ({\text{Sa}}_{{\text{O}}_{2}}\times 1.34{\tfrac {\text{mL}}{\text{g Hb}}}\times {\text{Hb}})+({\text{O}}_{2}{\text{ carriage in blood}}\times {\text{Pa}}_{{\text{O}}_{2}})}$

The hypoxia leads to an increase in minute ventilation (hence both low CO₂, and subsequently bicarbonate), Hb increases through haemoconcentration and erythrogenesis. Alkalosis shifts the haemoglobin dissociation constant to the left, 2,3-BPG increases to counter this. Cardiac output increases through an increase in heart rate.

The body's response to high altitude includes the following:

• ↑ Erythropoietin → ↑ hematocrit and haemoglobin
• ↑ 2,3-BPG (allows ↑ release of O₂ and a right shift on the Hb-O₂ disassociation curve)
• ↑ kidney excretion of bicarbonate (use of acetazolamide can augment for treatment)
• Chronic hypoxic pulmonary vasoconstriction (can cause right ventricular hypertrophy)

People with high-altitude sickness generally have reduced hyperventilator response, impaired gas exchange, fluid retention or increased sympathetic drive. There is thought to be an increase in cerebral venous volume because of an increase in cerebral blood flow and hypocapnic cerebral vasoconstriction causing oedema.

Diagnosis

Altitude sickness is typically self-diagnosed since symptoms are consistent: nausea, vomiting, headache, and can generally be deduced from a rapid change in altitude or oxygen levels. However, some symptoms may be confused with dehydration. Some severe cases may require professional diagnosis which can be assisted with multiple different methods such as using an MRI or CT scan to check for abnormal buildup of fluids in the lung or brain.

Prevention

Ascending slowly is the best way to avoid altitude sickness. Avoiding strenuous activity such as skiing, hiking, etc. in the first 24 hours at high altitude may reduce the symptoms of AMS. Alcohol and sleeping pills are respiratory depressants, and thus slow down the acclimatization process and should be avoided. Alcohol also tends to cause dehydration and exacerbates AMS. Thus, avoiding alcohol consumption in the first 24–48 hours at a higher altitude is optimal.

Pre-acclimatization

Pre-acclimatization is when the body develops tolerance to low oxygen concentrations before ascending to an altitude. It significantly reduces risk because less time has to be spent at altitude to acclimatize in the traditional way. Additionally, because less time has to be spent on the mountain, less food and supplies have to be taken up. Several commercial systems exist that use altitude tents, so called because they mimic altitude by reducing the percentage of oxygen in the air while keeping air pressure constant to the surroundings. Examples of pre-acclimation measures include remote ischaemic preconditioning, using hypobaric air breathing in order to simulate altitude, and positive end-expiratory pressure.

Altitude acclimatization

Altitude acclimatization is the process of adjusting to decreasing oxygen levels at higher elevations, in order to avoid altitude sickness. Once above approximately 3,000 metres (10,000 ft) – a pressure of 70 kilopascals (0.69 atm) – most climbers and high-altitude trekkers take the "climb-high, sleep-low" approach. For high-altitude climbers, a typical acclimatization regimen might be to stay a few days at a base camp, climb up to a higher camp (slowly), and then return to base camp. A subsequent climb to the higher camp then includes an overnight stay. This process is then repeated a few times, each time extending the time spent at higher altitudes to let the body adjust to the oxygen level there, a process that involves the production of additional red blood cells. Once the climber has acclimatized to a given altitude, the process is repeated with camps placed at progressively higher elevations. The rule of thumb is to ascend no more than 300 m (1,000 ft) per day to sleep. That is, one can climb from 3,000 m (9,800 ft) (70 kPa or 0.69 atm) to 4,500 m (15,000 ft) (58 kPa or 0.57 atm) in one day, but one should then descend back to 3,300 m (10,800 ft) (67.5 kPa or 0.666 atm) to sleep. This process cannot safely be rushed, and this is why climbers need to spend days (or even weeks at times) acclimatizing before attempting to climb a high peak. Simulated altitude equipment such as altitude tents provide hypoxic (reduced oxygen) air, and are designed to allow partial pre-acclimation to high altitude, reducing the total time required on the mountain itself.

Altitude acclimatization is necessary for some people who move rapidly from lower altitudes to higher altitudes .

Medications

The drug acetazolamide (trade name Diamox) may help some people making a rapid ascent to sleeping altitude above 2,700 metres (9,000 ft), and it may also be effective if started early in the course of AMS. Acetazolamide can be taken before symptoms appear as a preventive measure at a dose of 125 mg twice daily. The Everest Base Camp Medical Centre cautions against its routine use as a substitute for a reasonable ascent schedule, except where rapid ascent is forced by flying into high altitude locations or due to terrain considerations. The Centre suggests a dosage of 125 mg twice daily for prophylaxis, starting from 24 hours before ascending until a few days at the highest altitude or on descending; with 250 mg twice daily recommended for treatment of AMS.^[21] The Centers for Disease Control and Prevention (CDC) suggest the same dose for prevention of 125 mg acetazolamide every 12 hours. Acetazolamide, a mild diuretic, works by stimulating the kidneys to secrete more bicarbonate in the urine, thereby acidifying the blood. This change in pH stimulates the respiratory center to increase the depth and frequency of respiration, thus speeding the natural acclimatization process. An undesirable side-effect of acetazolamide is a reduction in aerobic endurance performance. Other minor side effects include a tingle-sensation in hands and feet. Although a sulfonamide; acetazolamide is a non-antibiotic and has not been shown to cause life-threatening allergic cross-reactivity in those with a self-reported sulfonamide allergy. Dosage of 1000 mg/day will produce a 25% decrease in performance, on top of the reduction due to high-altitude exposure. The CDC advises that Dexamethasone be reserved for treatment of severe AMS and HACE during descents, and notes that Nifedipine may prevent HAPE.

There is insufficient evidence to determine the safety of sumatriptan and if it may help prevent altitude sickness. Despite their popularity, antioxidant treatments have not been found to be effective medications for prevention of AMS. Interest in phosphodiesterase inhibitors such as sildenafil has been limited by the possibility that these drugs might worsen the headache of mountain sickness. A promising possible preventive for altitude sickness is myo-inositol trispyrophosphate (ITPP), which increases the amount of oxygen released by hemoglobin.

Prior to the onset of altitude sickness, ibuprofen is a suggested non-steroidal anti-inflammatory and painkiller that can help alleviate both the headache and nausea associated with AMS. It has not been studied for the prevention of cerebral edema (swelling of the brain) associated with extreme symptoms of AMS.

Over-the-counter herbal supplements and traditional medicines

Herbal supplements and traditional medicines are sometimes suggested to prevent high altitude sickness including ginkgo biloba, R crenulata, minerals such as iron, antacids, and hormonal-based supplements such as medroxyprogesterone and erythropoietin. Medical evidence to support the effectiveness and safety of these approaches is often contradictory or lacking. Indigenous peoples of the Americas, such as the Aymaras of the Altiplano, have for centuries chewed coca leaves to try to alleviate the symptoms of mild altitude sickness. This therapy has not yet been proven effective in a clinical study.^[31] In Chinese and Tibetan traditional medicine, an extract of the root tissue of Radix rhodiola is often taken in order to prevent the symptoms of high altitude sickness, however, no clear medical studies have confirmed the effectiveness or safety of this extract.

Oxygen enrichment

In high-altitude conditions, oxygen enrichment can counteract the hypoxia related effects of altitude sickness. A small amount of supplemental oxygen reduces the equivalent altitude in climate-controlled rooms. At 3,400 metres (11,200 ft) (67 kPa or 0.66 atm), raising the oxygen concentration level by 5% via an oxygen concentrator and an existing ventilation system provides an effective altitude of 3,000 m (10,000 ft) (70 kPa or 0.69 atm), which is more tolerable for those unaccustomed to high altitudes.

Oxygen from gas bottles or liquid containers can be applied directly via a nasal cannula or mask. Oxygen concentrators based upon pressure swing adsorption (PSA), VSA, or vacuum-pressure swing adsorption (VPSA) can be used to generate the oxygen if electricity is available. Stationary oxygen concentrators typically use PSA technology, which has performance degradations at the lower barometric pressures at high altitudes. One way to compensate for the performance degradation is to use a concentrator with more flow capacity. There are also portable oxygen concentrators that can be used on vehicular DC power or on internal batteries, and at least one system commercially available measures and compensates for the altitude effect on its performance up to 4,000 m (13,000 ft). The application of high-purity oxygen from one of these methods increases the partial pressure of oxygen by raising the FiO₂ (fraction of inspired oxygen).

Other methods

Increased water intake may also help in acclimatization to replace the fluids lost through heavier breathing in the thin, dry air found at altitude, although consuming excessive quantities ("over-hydration") has no benefits and may cause dangerous hyponatremia.

Treatment

The only reliable treatment, and in many cases the only option available, is to descend. Attempts to treat or stabilize the patient in situ (at altitude) are dangerous unless highly controlled and with good medical facilities. However, the following treatments have been used when the patient's location and circumstances permit:

• Oxygen may be used for mild to moderate AMS below 3,700 metres (12,000 ft) and is commonly provided by physicians at mountain resorts. Symptoms abate in 12 to 36 hours without the need to descend.
• For more serious cases of AMS, or where rapid descent is impractical, a Gamow bag, a portable plastic hyperbaric chamber inflated with a foot pump, can be used to reduce the effective altitude by as much as 1,500 m (5,000 ft). A Gamow bag is generally used only as an aid to evacuate severe AMS patients, not to treat them at altitude.
• Acetazolamide 250 mg twice daily dosing assists in AMS treatment by quickening altitude acclimatization. A study by the Denali Medical Research Project concluded: "In established cases of acute mountain sickness, treatment with acetazolamide relieves symptoms, improves arterial oxygenation, and prevents further impairment of pulmonary gas exchange."
• The folk remedy for altitude sickness in Ecuador, Peru and Bolivia is a tea made from the coca plant. See mate de coca.
• Steroids can be used to treat the symptoms of pulmonary or cerebral edema, but do not treat the underlying AMS.
• Two studies in 2012 showed that Ibuprofen 600 milligrams three times daily was effective at decreasing the severity and incidence of AMS; it was not clear if HAPE or HACE was affected.
• Paracetamol (acetaminophen) has also shown to be as good as ibuprofen for altitude sickness when tested on climbers ascending Everest.

Domain-specific language

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Domain-specific_language 

A domain-specific language (DSL) is a computer language specialized to a particular application domain. This is in contrast to a general-purpose language (GPL), which is broadly applicable across domains. There are a wide variety of DSLs, ranging from widely used languages for common domains, such as HTML for web pages, down to languages used by only one or a few pieces of software, such as MUSH soft code. DSLs can be further subdivided by the kind of language, and include domain-specific markup languages, domain-specific modeling languages (more generally, specification languages), and domain-specific programming languages. Special-purpose computer languages have always existed in the computer age, but the term "domain-specific language" has become more popular due to the rise of domain-specific modeling. Simpler DSLs, particularly ones used by a single application, are sometimes informally called mini-languages.

The line between general-purpose languages and domain-specific languages is not always sharp, as a language may have specialized features for a particular domain but be applicable more broadly, or conversely may in principle be capable of broad application but in practice used primarily for a specific domain. For example, Perl was originally developed as a text-processing and glue language, for the same domain as AWK and shell scripts, but was mostly used as a general-purpose programming language later on. By contrast, PostScript is a Turing-complete language, and in principle can be used for any task, but in practice is narrowly used as a page description language.

Use

The design and use of appropriate DSLs is a key part of domain engineering, by using a language suitable to the domain at hand – this may consist of using an existing DSL or GPL, or developing a new DSL. Language-oriented programming considers the creation of special-purpose languages for expressing problems as standard part of the problem-solving process. Creating a domain-specific language (with software to support it), rather than reusing an existing language, can be worthwhile if the language allows a particular type of problem or solution to be expressed more clearly than an existing language would allow and the type of problem in question reappears sufficiently often. Pragmatically, a DSL may be specialized to a particular problem domain, a particular problem representation technique, a particular solution technique, or other aspects of a domain.

Overview

A domain-specific language is created specifically to solve problems in a particular domain and is not intended to be able to solve problems outside of it (although that may be technically possible). In contrast, general-purpose languages are created to solve problems in many domains. The domain can also be a business area. Some examples of business areas include:

• life insurance policies (developed internally by a large insurance enterprise)
• combat simulation
• salary calculation
• billing

A domain-specific language is somewhere between a tiny programming language and a scripting language, and is often used in a way analogous to a programming library. The boundaries between these concepts are quite blurry, much like the boundary between scripting languages and general-purpose languages.

In design and implementation

Domain-specific languages are languages (or often, declared syntaxes or grammars) with very specific goals in design and implementation. A domain-specific language can be one of a visual diagramming language, such as those created by the Generic Eclipse Modeling System, programmatic abstractions, such as the Eclipse Modeling Framework, or textual languages. For instance, the command line utility grep has a regular expression syntax which matches patterns in lines of text. The sed utility defines a syntax for matching and replacing regular expressions. Often, these tiny languages can be used together inside a shell to perform more complex programming tasks.

The line between domain-specific languages and scripting languages is somewhat blurred, but domain-specific languages often lack low-level functions for filesystem access, interprocess control, and other functions that characterize full-featured programming languages, scripting or otherwise. Many domain-specific languages do not compile to byte-code or executable code, but to various kinds of media objects: GraphViz exports to PostScript, GIF, JPEG, etc., where Csound compiles to audio files, and a ray-tracing domain-specific language like POV compiles to graphics files. A computer language like SQL presents an interesting case: it can be deemed a domain-specific language because it is specific to a specific domain (in SQL's case, accessing and managing relational databases), and is often called from another application, but SQL has more keywords and functions than many scripting languages, and is often thought of as a language in its own right, perhaps because of the prevalence of database manipulation in programming and the amount of mastery required to be an expert in the language.

Further blurring this line, many domain-specific languages have exposed APIs, and can be accessed from other programming languages without breaking the flow of execution or calling a separate process, and can thus operate as programming libraries.

Programming tools

Some domain-specific languages expand over time to include full-featured programming tools, which further complicates the question of whether a language is domain-specific or not. A good example is the functional language XSLT, specifically designed for transforming one XML graph into another, which has been extended since its inception to allow (particularly in its 2.0 version) for various forms of filesystem interaction, string and date manipulation, and data typing.

In model-driven engineering, many examples of domain-specific languages may be found like OCL, a language for decorating models with assertions or QVT, a domain-specific transformation language. However, languages like UML are typically general-purpose modeling languages.

To summarize, an analogy might be useful: a Very Little Language is like a knife, which can be used in thousands of different ways, from cutting food to cutting down trees. A domain-specific language is like an electric drill: it is a powerful tool with a wide variety of uses, but a specific context, namely, putting holes in things. A General Purpose Language is a complete workbench, with a variety of tools intended for performing a variety of tasks. Domain-specific languages should be used by programmers who, looking at their current workbench, realize they need a better drill and find that a particular domain-specific language provides exactly that.

Domain-specific language topics

External and Embedded Domain Specific Languages

DSLs implemented via an independent interpreter or compiler are known as External Domain Specific Languages. Well known examples include LaTeX or AWK. A separate category known as Embedded (or Internal) Domain Specific Languages are typically implemented within a host language as a library and tend to be limited to the syntax of the host language, though this depends on host language capabilities.

Usage patterns

There are several usage patterns for domain-specific languages:

• Processing with standalone tools, invoked via direct user operation, often on the command line or from a Makefile (e.g., grep for regular expression matching, sed, lex, yacc, the GraphViz toolset, etc.)
• Domain-specific languages which are implemented using programming language macro systems, and which are converted or expanded into a host general purpose language at compile-time or realtime
• embedded domain-specific language (eDSL), implemented as libraries which exploit the syntax of their host general purpose language or a subset thereof while adding domain-specific language elements (data types, routines, methods, macros etc.). (e.g. jQuery, React, Embedded SQL, LINQ)
• Domain-specific languages which are called (at runtime) from programs written in general purpose languages like C or Perl, to perform a specific function, often returning the results of operation to the "host" programming language for further processing; generally, an interpreter or virtual machine for the domain-specific language is embedded into the host application (e.g. format strings, a regular expression engine)
• Domain-specific languages which are embedded into user applications (e.g., macro languages within spreadsheets) and which are (1) used to execute code that is written by users of the application, (2) dynamically generated by the application, or (3) both.

Many domain-specific languages can be used in more than one way. DSL code embedded in a host language may have special syntax support, such as regexes in sed, AWK, Perl or JavaScript, or may be passed as strings.

Design goals

Adopting a domain-specific language approach to software engineering involves both risks and opportunities. The well-designed domain-specific language manages to find the proper balance between these.

Domain-specific languages have important design goals that contrast with those of general-purpose languages:

• Domain-specific languages are less comprehensive.
• Domain-specific languages are much more expressive in their domain.
• Domain-specific languages should exhibit minimal redundancy.

Idioms

In programming, idioms are methods imposed by programmers to handle common development tasks, e.g.:

• Ensure data is saved before the window is closed.
• Edit code whenever command-line parameters change because they affect program behavior.

General purpose programming languages rarely support such idioms, but domain-specific languages can describe them, e.g.:

• A script can automatically save data.
• A domain-specific language can parameterize command line input.

Examples

Examples of domain-specific languages include HTML, Logo for pencil-like drawing, Verilog and VHDL hardware description languages, MATLAB and GNU Octave for matrix programming, Mathematica, Maple and Maxima for symbolic mathematics, Specification and Description Language for reactive and distributed systems, spreadsheet formulas and macros, SQL for relational database queries, YACC grammars for creating parsers, regular expressions for specifying lexers, the Generic Eclipse Modeling System for creating diagramming languages, Csound for sound and music synthesis, and the input languages of GraphViz and GrGen, software packages used for graph layout and graph rewriting, Hashicorp Configuration Language used for Terraform and other Hashicorp tools, Puppet also has its own configuration language.

GameMaker Language

The GML scripting language used by GameMaker Studio is a domain-specific language targeted at novice programmers to easily be able to learn programming. While the language serves as a blend of multiple languages including Delphi, C++, and BASIC, there is a lack of structures, data types, and other features of a full-fledged programming language. Many of the built-in functions are sandboxed for the purpose of easy portability. The language primarily serves to make it easy for anyone to pick up the language and develop a game.

ColdFusion Markup Language

ColdFusion's associated scripting language is another example of a domain-specific language for data-driven websites. This scripting language is used to weave together languages and services such as Java, .NET, C++, SMS, email, email servers, http, ftp, exchange, directory services, and file systems for use in websites.

The ColdFusion Markup Language (CFML) includes a set of tags that can be used in ColdFusion pages to interact with data sources, manipulate data, and display output. CFML tag syntax is similar to HTML element syntax.

Erlang OTP

The Erlang Open Telecom Platform was originally designed for use inside Ericsson as a domain-specific language. The language itself offers a platform of libraries to create finite state machines, generic servers and event managers that quickly allow an engineer to deploy applications, or support libraries, that have been shown in industry benchmarks to outperform other languages intended for a mixed set of domains, such as C and C++. The language is now officially open source and can be downloaded from their website.

FilterMeister

FilterMeister is a programming environment, with a programming language that is based on C, for the specific purpose of creating Photoshop-compatible image processing filter plug-ins; FilterMeister runs as a Photoshop plug-in itself and it can load and execute scripts or compile and export them as independent plug-ins. Although the FilterMeister language reproduces a significant portion of the C language and function library, it contains only those features which can be used within the context of Photoshop plug-ins and adds a number of specific features only useful in this specific domain.

MediaWiki templates

The Template feature of MediaWiki is an embedded domain-specific language whose fundamental purpose is to support the creation of page templates and the transclusion (inclusion by reference) of MediaWiki pages into other MediaWiki pages.

Software engineering uses

There has been much interest in domain-specific languages to improve the productivity and quality of software engineering. Domain-specific language could possibly provide a robust set of tools for efficient software engineering. Such tools are beginning to make their way into the development of critical software systems.

The Software Cost Reduction Toolkit is an example of this. The toolkit is a suite of utilities including a specification editor to create a requirements specification, a dependency graph browser to display variable dependencies, a consistency checker to catch missing cases in well-formed formulas in the specification, a model checker and a theorem prover to check program properties against the specification, and an invariant generator that automatically constructs invariants based on the requirements.

A newer development is language-oriented programming, an integrated software engineering methodology based mainly on creating, optimizing, and using domain-specific languages.

Metacompilers

Further information: Metacompiler

Complementing language-oriented programming, as well as all other forms of domain-specific languages, are the class of compiler writing tools called metacompilers. A metacompiler is not only useful for generating parsers and code generators for domain-specific languages, but a metacompiler itself compiles a domain-specific metalanguage specifically designed for the domain of metaprogramming.

Besides parsing domain-specific languages, metacompilers are useful for generating a wide range of software engineering and analysis tools. The meta-compiler methodology is often found in program transformation systems.

Metacompilers that played a significant role in both computer science and the computer industry include Meta-II, and its descendant TreeMeta.

Unreal Engine before version 4 and other games

Unreal and Unreal Tournament unveiled a language called UnrealScript. This allowed for rapid development of modifications compared to the competitor Quake (using the Id Tech 2 engine). The Id Tech engine used standard C code meaning C had to be learned and properly applied, while UnrealScript was optimized for ease of use and efficiency. Similarly, the development of more recent games introduced their own specific languages, one more common example is Lua for scripting.

Rules Engines for Policy Automation

Various Business Rules Engines have been developed for automating policy and business rules used in both government and private industry. ILOG, Oracle Policy Automation, DTRules, Drools and others provide support for DSLs aimed to support various problem domains. DTRules goes so far as to define an interface for the use of multiple DSLs within a Rule Set.

The purpose of Business Rules Engines is to define a representation of business logic in as human-readable fashion as possible. This allows both subject-matter experts and developers to work with and understand the same representation of the business logic. Most Rules Engines provide both an approach to simplifying the control structures for business logic (for example, using Declarative Rules or Decision Tables) coupled with alternatives to programming syntax in favor of DSLs.

Statistical modelling languages

Statistical modelers have developed domain-specific languages such as R (an implementation of the S language), Bugs, Jags, and Stan. These languages provide a syntax for describing a Bayesian model and generate a method for solving it using simulation.

Generate model and services to multiple programming Languages

Generate object handling and services based on an Interface Description Language for a domain-specific language such as JavaScript for web applications, HTML for documentation, C++ for high-performance code, etc. This is done by cross-language frameworks such as Apache Thrift or Google Protocol Buffers.

Gherkin

Gherkin is a language designed to define test cases to check the behavior of software, without specifying how that behavior is implemented. It is meant to be read and used by non-technical users using a natural language syntax and a line-oriented design. The tests defined with Gherkin must then be implemented in a general programming language. Then, the steps in a Gherkin program acts as a syntax for method invocation accessible to non-developers.

Other examples

Other prominent examples of domain-specific languages include:

• Emacs Lisp
• Game Description Language
• OpenGL Shading Language
• Gradle
• ActionScript

Advantages and disadvantages

Some of the advantages:

• Domain-specific languages allow solutions to be expressed in the idiom and at the level of abstraction of the problem domain. The idea is that domain experts themselves may understand, validate, modify, and often even develop domain-specific language programs. However, this is seldom the case.
• Domain-specific languages allow validation at the domain level. As long as the language constructs are safe any sentence written with them can be considered safe.
• Domain-specific languages can help to shift the development of business information systems from traditional software developers to the typically larger group of domain-experts who (despite having less technical expertise) have a deeper knowledge of the domain.
• Domain-specific languages are easier to learn, given their limited scope.

Some of the disadvantages:

• Cost of learning a new language
• Limited applicability
• Cost of designing, implementing, and maintaining a domain-specific language as well as the tools required to develop with it (IDE)
• Finding, setting, and maintaining proper scope.
• Difficulty of balancing trade-offs between domain-specificity and general-purpose programming language constructs.
• Potential loss of processor efficiency compared with hand-coded software.
• Proliferation of similar non-standard domain-specific languages, for example, a DSL used within one insurance company versus a DSL used within another insurance company.
• Non-technical domain experts can find it hard to write or modify DSL programs by themselves.
• Increased difficulty of integrating the DSL with other components of the IT system (as compared to integrating with a general-purpose language).
• Low supply of experts in a particular DSL tends to raise labor costs.
• Harder to find code examples.

Tools for designing domain-specific languages

• JetBrains MPS is a tool for designing domain-specific languages. It uses projectional editing which allows overcoming the limits of language parsers and building DSL editors, such as ones with tables and diagrams. It implements language-oriented programming. MPS combines an environment for language definition, a language workbench, and an Integrated Development Environment (IDE) for such languages.
• MontiCore is a language workbench for the efficient development of domain-specific languages. It processes an extended grammar format that defines the DSL and generates Java components for processing the DSL documents.
• Xtext is an open-source software framework for developing programming languages and domain-specific languages (DSLs). Unlike standard parser generators, Xtext generates not only a parser but also a class model for the abstract syntax tree. In addition, it provides a fully featured, customizable Eclipse-based IDE.
• Racket is a cross-platform language toolchain including native code, JIT and Javascript compiler, IDE (in addition to supporting Emacs, Vim, VSCode and others) and command line tools designed to accommodate creating both domain-specific and general purpose languages.

Sustainable business

From Wikipedia, the free encyclopedia
https://en.wikipedia.org/wiki/Sustainable_business

A sustainable business, or a green business, is an enterprise that has minimal negative impact or potentially a positive effect on the global or local environment, community, society, or economy—a business that strives to meet the triple bottom line. They cluster under different groupings and the whole is sometimes referred to as "green capitalism." Often, sustainable businesses have progressive environmental and human rights policies. In general, business is described as green if it matches the following four criteria:

1. It incorporates principles of sustainability into each of its business decisions.
2. It supplies environmentally friendly products or services that replaces demand for nongreen products and/or services.
3. It is greener than traditional competition.
4. It has made an enduring commitment to environmental principles in its business operations.

Terminology

A sustainable business is any organization that participates in Environmentally friendly or green activities to ensure that all processes, products, and manufacturing activities adequately address current environmental concerns while maintaining a profit. In other words, it is a business that “meets the needs of the present [world] without compromising the ability of future generations to meet their own needs.” It is the process of assessing how to design products that will take advantage of the current environmental situation and how well a company’s products perform with renewable resources.

The Brundtland Report emphasized that sustainability is a three-legged stool of people, planet, and profit. Sustainable businesses with the supply chain try to balance all three through the triple-bottom-line concept—using sustainable development and sustainable distribution to affect the environment, business growth, and the society.

Everyone affects the sustainability of the marketplace and the planet in some way. Sustainable development within a business can create value for customers, investors, and the environment. A sustainable business must meet customer needs while, at the same time, treating the environment well. To succeed in such an approach, where stakeholder balancing and joint solutions are key, requires a structural approach. One philosophy, that includes many different tools and methods, is the concept of Sustainable Enterprise Excellence. Another is the adoption of the concept of responsible growth.

Sustainability is often confused with corporate social responsibility (CSR), though the two are not the same. Bansal and DesJardine (2014) state that the notion of ‘time’ discriminates sustainability from CSR and other similar concepts. Whereas ethics, morality, and norms permeate CSR, sustainability only obliges businesses to make intertemporal trade-offs to safeguard intergenerational equity. Short-termism is the bane of sustainability. While CSR and sustainability are not the same, they are related to each other. Determining salaries, implementing new technology, and retiring old plants all have an impact on the firms stakeholder's and the natural environment. Green business has been seen as a possible mediator of economic-environmental relations, and if proliferated, would serve to diversify our economy, even if it has a negligible effect at lowering atmospheric CO₂ levels. The definition of "green jobs" is ambiguous, but it is generally agreed that these jobs, the result of green business, should be linked to "clean energy" and contribute to the reduction of greenhouse gases. These corporations can be seen as generators of not only "green energy", but as producers of new "materialities" that are the product of the technologies, these firms developed and deployed.

Environmental sphere

A major initiative of sustainable businesses is to eliminate or decrease the environmental harm caused by the production and consumption of their goods. The impact of such human activities in terms of the number of greenhouse gases produced can be measured in units of carbon dioxide and is referred to as the carbon footprint. The carbon footprint concept is derived from the ecological footprint analysis, which examines the ecological capacity required to support the consumption of products.

Businesses take a wide range of green initiatives. One of the most common examples is the act of "going paperless" or sending electronic correspondence in lieu of paper when possible. On a higher level, examples of sustainable business practices include: refurbishing used products (e.g., tuning up lightly used commercial fitness equipment for resale); revising production processes to eliminate waste (such as using a more accurate template to cut out designs), and choosing nontoxic raw materials and processes. For example, Canadian farmers have found that hemp is a sustainable alternative to rapeseed in their traditional crop rotation; hemp grown for fiber or seed requires no pesticides or herbicides.

Sustainable business leaders also take into account the life cycle costs for the items they produce. Input costs must be considered regarding regulations, energy use, storage, and disposal. Designing for the environment DFE is also an element of sustainable business. This process enables users to consider the potential environmental impacts of a product and the process used to make that product.

The many possibilities for adopting green practices have led to considerable pressure being put upon companies from consumers, employees, government regulators, and other stakeholders. Some companies have resorted to greenwashing instead of making meaningful changes, merely marketing their products in ways that suggest green practices. For example, various producers in the bamboo fiber industry have been taken to court for advertising their products as more "green" than they are. Still, countless other companies have taken the sustainability trend seriously and are enjoying profits. In their book “Corporate Sustainability in International Comparison”, Schaltegger et al. (2014) analyzes the current state of corporate sustainability management and corporate social responsibility across eleven countries. Their research is based on an extensive survey focusing on the companies’ intention to pursue sustainability management (i.e. motivation; issues), the integration of sustainability in the organization (i.e. connecting sustainability to the core business; involving corporate functions; using drivers of business cases for sustainability) and the actual implementation of sustainability management measures (i.e. stakeholder management; sustainability management tools and standards; measurements). The Gort Cloud written by Richard Seireeni, (2009), documents the experiences of sustainable businesses in America and their reliance on the vast but invisible green community, referred to as the gort cloud, for support and a market.

Green investment firms are consequently attracting unprecedented interest. In the UK, for instance, the Green Investment Bank is devoted exclusively to supporting renewable domestic energy. However, the UK and Europe as a whole are falling behind the impressive pace set by developing nations in terms of green development. Thus, green investment firms are creating more and more opportunities to support sustainable development practices in emerging economies. By providing micro-loans and larger investments, these firms assist small business owners in developing nations who seek business education, affordable loans, and new distribution networks for their "green" products.

An effective way for businesses to contribute towards waste reduction is to remanufacture products so that the materials used can have a longer life-span.

Sustainable Businesses

The Harvard Business School business historian Geoffrey Jones (academic) has traced the historical origins of green business back to pioneering start-ups in organic food and wind and solar energy before World War 1. Among large corporations, Ford Motor Company occupies an odd role in the story of sustainability. Ironically, founder Henry Ford was a pioneer in the sustainable business realm, experimenting with plant-based fuels during the days of the Model T. Ford Motor Company also shipped the Model A truck in crates that then became the vehicle floorboards at the factory destination. This was a form of upcycling, retaining high quality in a closed-loop industrial cycle. Furthermore, the original auto body was made of a stronger-than-steel hemp composite. Today, of course, Fords aren't made of hemp nor do they run on the most sensible fuel. Currently, Ford's claim to eco-friendly fame is the use of seat fabric made from 100% post-industrial materials and renewable soy foam seat bases. Ford executives recently appointed the company’s first senior vice president of sustainability, environment, and safety engineering. This position is responsible for establishing a long-range sustainability strategy and environmental policy, developing the products and processes necessary to satisfy customers and society as a whole while working toward energy independence. It remains to be seen whether Ford will return to its founder's vision of a petroleum-free automobile, a vehicle powered by the remains of plant matter.

The automobile manufacturer Subaru has also made efforts to tackle sustainability. In 2008 a Subaru assembly plant in Lafayette became the first auto manufacturer to achieve zero landfill status when the plant implemented sustainable policies. The company successfully managed to implement a plan that increased refuse recycling to 99.8%. In 2012, the corporation increased the reuse of Styrofoam by 9%. And from the year 2008 to the year 2012, environmental incidents and accidents reduced from 18 to 4.

Smaller companies such as Nature's Path, an organic cereal and snack making business, have also made sustainability gains in the 21st century. CEO Arran Stephens and his associates have ensured that the quickly growing company's products are produced without toxic farm chemicals. Furthermore, employees are encouraged to find ways to reduce consumption. Sustainability is an essential part of corporate discussions. Another example comes from Salt Spring Coffee, a company created in 1996 as a certified organic, fair trade, coffee producer. In recent years they have become carbon neutral, lowering emissions by reducing long-range trucking and using bio-diesel in delivery trucks, upgrading to energy efficient equipment and purchasing carbon offsets. The company claims to offer the first carbon neutral coffee sold in Canada. Salt Spring Coffee was recognized by the David Suzuki Foundation in the 2010 report Doing Business in a New Climate. A third example comes from Korea, where rice husks are used as a nontoxic packaging for stereo components and other electronics. The same material is later recycled to make bricks.

Some companies in the mining and specifically gold mining industries are attempting to move towards more sustainable practices, especially given that the industry is one of the most environmentally destructive. Indeed, regarding gold mining, Northwestern University scientists have, in the laboratory, discovered an inexpensive and environmentally sustainable method that uses simple cornstarch—instead of cyanide—to isolate gold from raw materials in a selective manner. Such a method will reduce the amount of cyanide released into the environment during gold extraction from raw ore, with one of the Northwestern University scientists, Sir Fraser Stoddart stating that: “The elimination of cyanide from the gold industry is of the utmost importance environmentally". Additionally, the retail jewelry industry is now trying to be more sustainable, with companies using green energy providers and recycling more, as well as preventing the use of mined-so called 'virgin gold' by applying re-finishing methods on pieces and re-selling them. Furthermore, the customer may opt for Fairtrade Gold, which gives a better deal to small scale and artisanal miners, and is an element of sustainable business. However, not all think that mining can be sustainable and much more must be done, noting that mining in general is in need of greater regional and international legislation and regulation, which is a valid point given the huge impact mining has on the planet and the huge number of products and goods that are made wholly or partly from mined materials.

In the luxury sector, in 2012, the group Kering developed the "Environmental Profit & Loss account" (EP&L) accounting method to track the progress of its sutainability goals, a strategy aligned with the UN Sustainable Development Goals. In 2019, on a request from the President Emmanuel Macron, François-Henri Pinault, Chairman and CEO of the luxury group Kering, presented the Fashion Pact during the summit, an initiative signed by 32 fashion firms committing to concrete measures to reduce their environmental impact. By 2020, 60 firms joined the Fashion Pact.

Social sphere

Organizations that give back to the community, whether through employees volunteering their time or through charitable donations are often considered socially sustainable. Organizations also can encourage education in their communities by training their employees and offering internships to younger members of the community. Practices such as these increase the education level and quality of life in the community.

For a business to be truly sustainable, it must sustain not only the necessary environmental resources, but also social resources—including employees, customers (the community), and its reputation.

A term that is directly relates to the social aspect of sustainability is Environmental justice. Sustainability and social justice are directly connected to one another, and seeing these as separate unrelated issues can lead to more problems for the environment and potentially businesses.

Consumers and Marketing

When people are choosing to purchase goods or services, they care what a company stands for. This includes social and environmental aspects that may not have seemed important in business in the past. Consumers nowadays are demanding more sustainable goods and services.  Because of this demand, companies must focus on their environmental impact to gain consumer loyalty. Because ecological awareness can be treated as a choice of personal taste rather than a necessity, it can be a method to try to increase capital from a marketing standpoint. When marketing a product or service it is important that a business is actually following through with environmental claims, and not just pretending to be in order to gain customers. False advertising leads to distrust among consumers and can ultimately end a company.

Greenwashing

With the idea of sustainability becoming more prevalent in the last decade, businesses must be aware of laws surrounding it and the potential legal implications. The Federal Trade Commission (FTC), Green guides are essentially a rulebook for businesses on how to avoid deceiving consumers with false advertising. This often is a problem when companies make vague or false environmental claims about a product or service they are selling. When this occurs it can be called "greenwashing". Greenwashing can also be described as the act of overexaggerating the beneficial effect the product has on the environment. If companies do not follow this guide they could be subject to legal ramifications. It is also important for green businesses to invest in experienced legal practitioners who can understand and can provide counsel on the FTC guidelines.

Organizations

The European community’s Restriction of Hazardous Substances Directive restricts the use of certain hazardous materials in the production of various electronic and electrical products. Waste Electrical and Electronic Equipment (WEEE) directives provide collection, recycling, and recovery practices for electrical goods. The World Business Council for Sustainable Development and the World Resources Institute are two organizations working together to set a standard for reporting on corporate carbon footprints. From October 2013, all quoted companies in the UK are legally required to report their annual greenhouse gas emissions in their directors’ report, under the Companies Act 2006 (Strategic and Directors’ Reports) Regulations 2013.

Lester Brown’s Plan B 2.0 and Hunter Lovins’s Natural Capitalism provide information on sustainability initiatives.

Corporate sustainability strategies

Corporate sustainability strategies can aim to take advantage of sustainable revenue opportunities, while protecting the value of business against increasing energy costs, the costs of meeting regulatory requirements, changes in the way customers perceive brands and products, and the volatile price of resources.

Not all eco-strategies can be incorporated into a company's Eco-portfolio immediately. The widely practiced strategies include: Innovation, Collaboration, Process Improvement and Sustainability reporting.

1. Innovation & Technology: This introverted method of sustainable corporate practices focuses on a company's ability to change its products and services towards less waste production.
2. Collaboration: The formation of networks with similar or partner companies facilitates knowledge sharing and propels innovation.
3. Process Improvement: Continuous process surveying and improvement are essential to reduction in waste. Employee awareness of company-wide sustainability plan further aids the integration of new and improved processes.
4. Sustainability Reporting: Periodic reporting of company performance in relation to goals. These goals are often incorporated into the corporate mission (as in the case of Ford Motor Co.).
5. Greening the Supply Chain: Sustainable procurement is important for any sustainability strategy as a company's impact on the environment is much bigger than the products that they consume. The B Corporation (certification) model is a good example of one that encourages companies to focus on this.

Additionally, companies might consider implementing a sound measurement and management system with readjustment procedures, as well as a regular forum for all stakeholders to discuss sustainability issues. The Sustainability Balanced Scorecard is a performance measurement and management system aiming at balancing financial and non-financial as well as short and long-term measures. It explicitly integrates strategically relevant environmental, social and ethical goals into the overall performance management system  and supports strategic sustainability management.

Standards

Enormous economic and population growth worldwide in the second half of the twentieth century aggravated the factors that threaten health and the world — ozone depletion, climate change, resource depletion, fouling of natural resources, and extensive loss of biodiversity and habitat. In the past, the standard approaches to environmental problems generated by business and industry have been regulatory-driven "end-of-the-pipe" remediation efforts. In the 1990s, efforts by governments, NGOs, corporations, and investors began to grow to develop awareness and plans for investment in business sustainability.

One critical milestone was the establishment of the ISO 14000 standards whose development came as a result of the Rio Summit on the Environment held in 1992. ISO 14001 is the cornerstone standard of the ISO 14000 series. It specifies a framework of control for an Environmental Management System against which an organization can be certified by a third party. Other ISO 14000 Series Standards are actually guidelines, many to help you achieve registration to ISO 14001. They include the following:

• ISO 14004 provides guidance on the development and implementation of environmental management systems
• ISO 14010 provides general principles of environmental auditing (now superseded by ISO 19011)
• ISO 14011 provides specific guidance on audit an environmental management system (now superseded by ISO 19011)
• ISO 14012 provides guidance on qualification criteria for environmental auditors and lead auditors (now superseded by ISO 19011)
• ISO 14013/5 provides audit program review and assessment material.
• ISO 14020+ labeling issues
• ISO 14030+ provides guidance on performance targets and monitoring within an Environmental Management System
• ISO 14040+ covers life cycle issues

Circular business models

Further information: Circular Economy

While the initial focus of academic, industry, and policy activities was mainly focused on the development of re-X (recycling, remanufacturing, reuse, recovery, ...) technology, it soon became clear that the technological capabilities increasingly exceed their implementation. For the transition towards a Circular Economy, different stakeholders have to work together. This shifted attention towards business model innovation as a key leverage for 'circular' technology adaption.

Circular business models are business models that are closing, narrowing, slowing, intensifying, and dematerializing loops, to minimize the resource inputs into and the waste and emission leakage out of the organizational system. This comprises recycling measures (closing), efficiency improvements (narrowing), use phase extensions (slowing or extending), a more intense use phase (intensifying), and the substitution of product utility by service and software solutions (dematerializing).

Certification

See also: Certification

Main article: Sustainability standards and certification

Challenges and opportunities

Implementing sustainable business practices may have an effect on profits and a firm's financial 'bottom line'. However, during a time where environmental awareness is popular, green strategies are likely to be embraced by employees, consumers, and other stakeholders. Organisations concerned about the environmental impact of their business are taking initiatives to invest in sustainable business practices. In fact, a positive correlation has been reported between environmental performance and economic performance. Businesses trying to implement sustainable business need to have insights on balancing the social equity, economic prosperity and environmental quality elements. 

If an organization’s current business model is inherently unsustainable, becoming truly sustainable requires a complete makeover of the business model (e.g. from selling cars to offering car sharing and other mobility services). This can present a major challenge due to the differences between the old and the new model and the respective skills, resources and infrastructure needed. A new business model can offer major opportunities by entering or even creating new markets and reaching new customer groups. The main challenges faced in the sustainable business practices implementation by businesses in developing countries include lack of skilled personnel, technological challenges, socio-economic challenges, organisational challenges and lack of proper policy framework. Skilled personnel plays a crucial role in quality management, enhanced compliance with international quality standards, preventative and operational maintenance attitude necessary to ensure sustainable business. In the absence of skilled labour forces, companies fail to implement a sustainable business model.

Another major challenge to the effective implementation of sustainable business is organisational challenges. Organisational challenges to the implementation of sustainable business activities arise from the difficulties associated with the planning, implementation and evaluation of sustainable business models. Addressing the organisational challenges for the implementation of sustainable business practices need to begin by analysing the whole supply chain of the business rather than focusing solely on the company's internal operations. Another major challenge is the lack of an appropriate policy framework for sustainable business. Companies comply with the lowest economic, social and environmental sustainability standards, when in fact the true sustainability in business operation can be achieved when the business is focused beyond compliance with integrated strategy and passion and purpose.

Companies leading the way in sustainable business practices can take advantage of sustainable revenue opportunities: according to the Department for Business, Innovation and Skills the UK green economy to grow by 4.9 to 5.5 percent a year by 2015, and the average internal rate of return on energy efficiency investments for large businesses is 48%. A 2013 survey suggests that demand for green products appears to be increasing: 27% of respondents said they are more likely to buy a sustainable product and/or service than 5 years ago. Furthermore, sustainable business practices may attract talent and generate tax breaks.