A specification often refers to a set of documented requirements to be
satisfied by a material, design, product, or service. A
specification is often a type of technical standard.
There are different types of technical or engineering specifications
(specs), and different usages of the term in different technical
contexts. They often refer to particular documents, and/or particular
information within them. The word specification is broadly defined as
"to state explicitly or in detail" or "to be specific".
Using the term "specification" without a clear indication of what kind
is confusing and considered bad practice.[according to whom?]
A requirement specification is a documented requirement, or set of
documented requirements, to be satisfied by a given material, design,
product, service, etc. It is a common early part of engineering
design and product development processes, in many fields.
A functional specification is a kind of requirement specification, and
may show functional block diagrams.
A design or product specification describes the features of the
solutions for the
Requirement Specification, referring to either a
designed solution or final produced solution. It is often used to
guide fabrication/production. Sometimes the term specification is here
used in connection with a data sheet (or spec sheet), which may be
confusing. A data sheet describes the technical characteristics of an
item or product, often published by a manufacturer to help people
choose or use the products. A data sheet is not a technical
specification in the sense of informing how to produce.
A "in-service" or "maintained as" specification, specifies the
conditions of a system or object after years of operation, including
the effects of wear and maintenance (configuration changes).
Specifications may also refer to technical standards, which may be
developed by any of various kinds of organizations, both public and
private. Example organization types include a corporation, a
consortium (a small group of corporations), a trade association (an
industry-wide group of corporations), a national government (including
its military, regulatory agencies, and national laboratories and
institutes), a professional association (society), a purpose-made
standards organization such as ISO, or vendor-neutral developed
generic requirements. It is common for one organization to refer to
(reference, call out, cite) the standards of another. Voluntary
standards may become mandatory if adopted by a government or business
2 Guidance and content
3 Construction specifications
3.1 Construction Specifications in North America
3.2 Construction specifications in Egypt
3.3 Construction specifications in the UK
Food and drug specifications
5 Information technology
5.1 Specification need
5.2 Formal specification
5.3 Architectural specification
5.4 Program specification
5.5 Functional specification
5.6 Web service specification
5.7 Document specification
6 See also
7 Notes and references
8 Further reading
In engineering, manufacturing, and business, it is vital for
suppliers, purchasers, and users of materials, products, or services
to understand and agree upon all requirements.
A specification may refer to a standard which is often referenced by a
contract or procurement document, or an otherwise agreed upon set of
requirements (though still often used in the singular). In any case,
it provides the necessary details about the specific requirements.
Standards for specifications may be provided by government agencies,
standards organizations (ASTM, ISO, CEN, DoD, etc.), trade
associations, corporations, and others. The following British
standards apply to specifications:
BS 7373-1:2001 Guide to the preparation of specifications 
BS 7373-2:2001 Product specifications. Guide to identifying criteria
for a product specification and to declaring product conformity 
BS 7373-3:2005, Product specifications. Guide to identifying criteria
for specifying a service offering 
A design/product specification does not necessarily prove a product to
be correct or useful in every context. An item might be verified to
comply with a specification or stamped with a specification number:
this does not, by itself, indicate that the item is fit for other,
non-validated uses. The people who use the item (engineers, trade
unions, etc.) or specify the item (building codes, government,
industry, etc.) have the responsibility to consider the choice of
available specifications, specify the correct one, enforce compliance,
and use the item correctly. Validation of suitability is necessary.
Guidance and content
Sometimes a guide or a standard operating procedure is available to
help write and format a good specification. A specification
Descriptive title, number, identifier, etc. of the specification
Date of last effective revision and revision designation
A logo or trademark to indicate the document copyright, ownership and
Table of Contents (TOC), if the document is long
Person, office, or agency responsible for questions on the
specification, updates, and deviations.
The significance, scope or importance of the specification and its
Terminology, definitions and abbreviations to clarify the meanings of
Test methods for measuring all specified characteristics
Material requirements: physical, mechanical, electrical, chemical,
etc. Targets and tolerances.
Acceptance testing, including Performance testing requirements.
Targets and tolerances.
Drawings, photographs, or technical illustrations
Safety considerations and requirements
Environmental considerations and requirements
Quality control requirements, acceptance sampling, inspections,
Person, office, or agency responsible for enforcement of the
Completion and delivery.
Provisions for rejection, reinspection, rehearing, corrective measures
References and citations for which any instructions in the content
maybe required to fulfill the traceability and clarity of the
Signatures of approval, if necessary
Change record to summarize the chronological development, revision and
completion if the document is to be circulated internally
Annexes and Appendices that are expand details, add clarification, or
Construction Specifications in North America
Specifications in North America form part of the contract documents
that accompany and govern the construction of building and
infrastructure projects. Specifications describe the quality and
performance of building materials, using code citations and published
standards, whereas the drawings or Building Information Model (BIM)
illustrates quantity and location of materials. The guiding master
document of names and numbers is the latest edition of MasterFormat.
This is a consensus document that is jointly sponsored by two
professional organizations: Construction Specifications Canada and
Construction Specifications Institute based in the United States and
updated every two years.
While there is a tendency to believe that "Specifications overrule
Drawings" in the event of discrepancies between the text document and
the drawings, the actual intent must be made explicit in the contract
between the Owner and the Contractor. The standard AIA (American
Institute of Architects) and EJCDC (
Engineering Joint Contract
Documents Committee) states that the drawings and specifications are
complementary, together providing the information required for a
complete facility. Many public agencies, such as the Naval Facilities
Command (NAVFAC) state that the specifications overrule the drawings.
This is based on the idea that words are easier for a jury (or
mediator) to interpret than drawings in case of a dispute.
The standard listing of construction specifications falls into 50
Divisions, or broad categories of work types and work results involved
in construction. The divisions are subdivided into sections, each one
addressing a specific material type (concrete) or a work product
(steel door) of the construction work. A specific material may be
covered in several locations, depending on the work result: stainless
steel (for example) can be covered as a sheet material used in
Flashing and Sheet Metal in Division 07; it can be part of a finished
product, such as a handrail, covered in Division 05; or it can be a
component of building hardware, covered in Division 08. The original
listing of specification divisions was based on the time sequence of
construction, working from exterior to interior, and this logic is
still somewhat followed as new materials and systems make their way
into the construction process.
Each Section is subdivided into three distinct Parts: "General",
"Products" and "Execution". The
MasterFormat and Section Format
system can be successfully applied to residential, commercial,
civil, and industrial construction. Although many
Architects find the
rather voluminous commercial style of specifications too lengthy for
most residential projects and therefore either produce more
abbreviated specifications of their own or use ArCHspec (which was
specifically created for residential projects). Master specification
systems are available from multiple vendors such as Arcom, Visispec,
BSD, and Spectext. These systems were created to standardize language
across the United States and are usually subscription based.
Specifications can be either "performance-based", whereby the
specifier restricts the text to stating the performance that must be
achieved by the completed work, "prescriptive" where the specifier
states the specific criteria such as fabrication standards applicable
to the item, or "proprietary", whereby the specifier indicates
specific products, vendors and even contractors that are acceptable
for each workscope. In addition, specifications can be "closed" with a
specific list of products, or "open" allowing for substitutions made
by the Contractor. Most construction specifications are a combination
of performance-based and proprietrary types, naming acceptable
manufacturers and products while also specifying certain standards and
design criteria that must be met.
While North American specifications are usually restricted to broad
descriptions of the work, European ones and Civil work can include
actual work quantities, including such things as area of drywall to be
built in square meters, like a bill of materials. This type of
specification is a collaborative effort between a specwriter and a
quantity surveyor. This approach is unusual in North America, where
each bidder performs a quantity survey on the basis of both drawings
and specifications. In many countries on the European continent,
content that might be described as "specifications" in the United
States are covered under the building code or municipal code. Civil
and infrastructure work in the United States often includes a quantity
breakdown of the work to be performed as well.
Although specifications are usually issued by the architect's office,
specification writing itself is undertaken by the architect and the
various engineers or by specialist specification writers.
Specification writing is often a distinct professional trade, with
professional certifications such as "Certified Construction Specifier"
(CCS) available through the Construction Specifications Institute and
the Registered Specification Writer (RSW) through Construction
Specifications Canada. Specification writers are either employees of
or sub-contractors to architects, engineers, or construction
management companies. Specification writers frequently meet with
manufacturers of building materials who seek to have their products
specified on upcoming construction projects so that contractors can
include their products in the estimates leading to their proposals.
In February 2015, ArCHspec went live, from ArCH (
Homes), a nationwide American professional society of
purpose is to improve residential architecture. ArCHspec was created
specifically for use by Licensed
Architects while designing SFR
(Single Family Residential) architectural projects. Unlike the more
commercial CSI (50+ division commercial specifications), ArCHspec
utilizes the more recognizable 16 traditional Divisions, plus a
Division 0 (Scope & Bid Forms) and Division 17 (low voltage). Many
architects, up to this point, did not provide specifications for
residential designs, which is one of the reasons ArCHspec was created:
to fill a void in the industry with more compact specifications for
residential use. Shorter form specifications documents suitable for
residential use are also available through Arcom, and follow the 50
division format, which was adopted in both the United States and
Canada starting in 2004. The 16 division format is no longer
considered standard, and is not supported by either CSI or CSC, or any
of the subscription master specification services, data repositories,
product lead systems, and the bulk of governmental agencies.
Construction specifications in Egypt
Egypt form part of contract documents. The Housing
and Building National Research Center (HBRC) is responsible for
developing construction specifications and codes. The HBRC has
published more than 15 books which cover building activities like
earthworks, plastering etc.
Construction specifications in the UK
Specifications in the UK are part of the contract documents that
accompany and govern the construction of a building. They are prepared
by construction professionals such as architects, architectural
technologists, structural engineers, landscape architects and building
services engineers. They are created from previous project
specifications, in-house documents or master specifications such as
National Building Specification (NBS). The National Building
Specification is owned by the Royal Institute of British Architects
(RIBA) through their commercial group RIBA Enterprises (RIBAe). NBS
master specifications provide content that is broad and comprehensive,
and delivered using software functionality that enables specifiers to
customize the content to suit the needs of the project and to keep up
UK project specification types fall into two main categories
prescriptive and performance. Prescriptive specifications define the
requirements using generic or proprietary descriptions of what is
required, whereas performance specifications focus on the outcomes
rather than the characteristics of the components.
Specifications are an integral part of Building Information Modeling
and cover the non-geometric requirements.
Food and drug specifications
Pharmaceutical products can usually be tested and qualified by various
Pharmacopoeia. Current existing pharmaceutical standards include:
The International Pharmacopoeia
United States Pharmacopeia
If any pharmaceutical product is not covered by the above standards,
it can be evaluated by the additional source of
other nations, from industrial specifications, or from a standardized
formulary such as
British National Formulary
British National Formulary for Children
British National Formulary
A similar approach is adopted by the food manufacturing, of which
Codex Alimentarius ranks the highest standards, followed by regional
and national standards.
The coverage of food and drug standards by ISO is currently less
fruitful and not yet put forward as an urgent agenda due to the tight
restrictions of regional or national constitution
Specifications and other standards can be externally imposed as
discussed above, but also internal manufacturing and quality
specifications. These exist not only for the food or pharmaceutical
product but also for the processing machinery, quality processes,
packaging, logistics (cold chain), etc. and are exemplified by ISO
14134 and ISO 15609
The converse of explicit statement of specifications is a process for
dealing with observations that are out-of-specification. The United
Food and Drug Administration has published a non-binding
recommendation that addresses just this point.
At the present time, much of the information and regulations
concerning food and food products remain in a form which makes it
difficult to apply automated information processing, storage and
transmission methods and techniques.
Data systems that can process, store and transfer information about
food and food products need formal specifications for the
representations of data about food and food products in order to
operate effectively and efficiently.
Development of formal specifications for food and drug data with the
necessary and sufficient clarity and precision for use specifically by
digital computing systems have begun to emerge from government
agencies and standards organizations.
The United States
Food and Drug Administration has published
specifications for a "Structured Product Label" which drug
manufacturers must by mandate use to submit electronically the
information on a drug label.
Recently, ISO has made some progress in the area of food and drug
standards and formal specifications for data about regulated
substances through the publication of ISO 11238
In many contexts, particularly software, specifications are needed to
avoid errors due to lack of compatibility, for instance, in
For instance, when two applications share Unicode data, but use
different normal forms or use them incorrectly, in an incompatible way
or without sharing a minimum set of interoperability specification,
errors and data loss can result. For example, Mac OS X has many
components that prefer or require only decomposed characters (thus
decomposed-only Unicode encoded with UTF-8 is also known as
"UTF8-MAC"). In one specific instance, the combination of OS X errors
handling composed characters, and the samba file- and printer-sharing
software (which replaces decomposed letters with composed ones when
copying file names), has led to confusing and data-destroying
Applications may avoid such errors by preserving input code points,
and only normalizing them to the application's preferred normal form
for internal use.
Such errors may also be avoided with algorithms normalizing both
strings before any binary comparison.
However errors due to file name encoding incompatibilities have always
existed, due to a lack of minimum set of common specification between
software hoped to be inter-operable between various file system
drivers, operating systems, network protocols, and thousands of
Main article: Formal specification
A formal specification is a mathematical description of software or
hardware that may be used to develop an implementation. It describes
what the system should do, not (necessarily) how the system should do
it. Given such a specification, it is possible to use formal
verification techniques to demonstrate that a candidate system design
is correct with respect to that specification. This has the advantage
that incorrect candidate system designs can be revised before a major
investment has been made in actually implementing the design. An
alternative approach is to use provably correct refinement steps to
transform a specification into a design, and ultimately into an actual
implementation, that is correct by construction.
In (hardware, software, or enterprise) systems development, an
architectural specification is the set of documentation that describes
the structure, behavior, and more views of that system.
A program specification is the definition of what a computer program
is expected to do. It can be informal, in which case it can be
considered as a user manual from a developer point of view, or formal,
in which case it has a definite meaning defined in mathematical or
programmatic terms. In practice, many successful specifications are
written to understand and fine-tune applications that were already
well-developed, although safety-critical software systems are often
carefully specified prior to application development. Specifications
are most important for external interfaces that must remain stable.
Main article: Functional specification
In software development, a functional specification (also, functional
spec or specs or functional specifications document (FSD)) is the set
of documentation that describes the behavior of a computer program or
larger software system. The documentation typically describes various
inputs that can be provided to the software system and how the system
responds to those inputs.
Web service specification
Further information: List of Web service specifications
Web services specifications are often under the umbrella of a quality
These types of documents define how a specific document should be
written, which may include, but is not limited to, the systems of a
document naming, version, layout, referencing, structuring,
appearance, language, copyright, hierarchy or format, etc.
Very often, this kind of specifications is complemented by a
Diagnostic design specification
Document management system
Identification of medicinal products
List of ISO standards
List of Air Ministry specifications
Manufacturing test requirement design specification
Product design specification
Publicly Available Specification
Specification and Description Language
Verification and validation
Notes and references
^ Form and Style of Standards,
ASTM Blue Book (PDF). ASTM
International. 2012. Retrieved 5 January 2013.
^ Form and Style of Standards,
ASTM Blue Book (PDF). ASTM
International. 2012. Retrieved 5 January 2013.
Gary Blake and Robert W. Bly, The Elements of Technical Writing, pg.
108. New York: Macmillan Publishers, 1993. ISBN 0020130856
^ BS 7373-1:2001
^ BS 7373-2:2001
^ BS 7373-3:2005
^ Stout, Peter. "Equipment Specification Writing Guide" (PDF).
Retrieved 15 June 2009.
^ "A Guide to Writing Specifications" (pdf). Los Angeles Unified
School District. Retrieved 8 November 2010.
^ "Defense and Program-Unique Specifications Format and Content"
(pdf). US Department of Defense. 2 April 2008. Retrieved 16 Sep
^ International Organization for Standardization. "01.080.01:
Graphical symbols in general". Retrieved 10 June 2009.
^ International Organization for Standardization. "ISO 10209".
Retrieved 10 June 2009.
^ a b International Organization for Standardization. "ISO 832:1994
Information and documentation -- Bibliographic description and
references -- Rules for the abbreviation of bibliographic terms".
Retrieved 10 June 2009.
^ ISO 690
^ International Organization for Standardization. "ISO 12615:2004
Bibliographic references and source identifiers for terminology work".
Retrieved 10 June 2009.
^ Title 21 CFR Part 11
^ a b IEEE. "PDF Specification for
IEEE Xplore" (PDF). Retrieved 27
^ Construction Specifications Institute
Food Standards Australia New Zealand. "Australia New Zealand Food
Standards Code". Archived from the original on 5 April 2008. Retrieved
6 April 2008.
Food labeling regulations
^ Hazard Analysis and Critical Control Points
^ International Organization for Standardization. "ISO 14134:2006
Optics and optical instruments -- Specifications for astronomical
telescopes". Retrieved 27 March 2009.
^ International Organization for Standardization. "ISO 15609:2004
Specification and qualification of welding procedures for metallic
materials -- Welding procedure specification". Retrieved 27 March
Center for Drug Evaluation and Research
Center for Drug Evaluation and Research (October 2006). Guidance for
Industry:Investigating Out-of-Specification (OOS) Test Results for
Pharmaceutical Production (PDF).
Food and Drug Administration.
Retrieved 20 May 2009.
^ United States
Food and Drug Administration. "Structured Product
Labeling Resources". Retrieved 29 August 2011.
^ International Organization for Standardization. "ISO/DIS 11238 --
Health Informatics --
Identification of medicinal products -- Data
elements and structures for the unique identification and exchange of
regulated information on substances". Retrieved 29 August 2011.
^ Stefanovic, Miladin; Matijević, Milan; Erić, Milan; Simic, Visnja;
et al. (2009). "Method of design and specification of web services
based on quality system documentation". Information Systems Frontiers.
11 (1): 75–86. doi:10.1007/s10796-008-9143-y.
^ Biodiversity Information Standards. "TDWG Standards Documentation
Specification". Retrieved 14 June 2009.
^ International Conference on Harmonisation of Technical Requirements
for Registration of Pharmaceuticals for Human Use. "ICH M2 EWG -
Electronic Common Technical Document Specification" (PDF). Retrieved
14 June 2009.
^ Delaney, Declan; Stephen Brown. "Document Templates for Student
Software Engineering" (PDF). Retrieved 14 June 2009.
Safety Standard Operating Procedure" (PDF). Retrieved 14 June
^ The University of Toledo. "Sample Standard Operating Procedure
Requirements for BSL2 Containment" (PDF). Retrieved 14 June
Pyzdek, T, "Quality
Engineering Handbook", 2003,
Godfrey, A. B., "Juran's Quality Handbook", 1999, ISBN 007034003X
"Specifications for the Chemical And Process Industries", 1996, ASQ
Quality Press, ISBN 0-87389-351-4
ASTM E29-06b Standard Practice for Using Significant Digits in Test
Data to Determine Conformance with Specifications
Journal of Chemical Information and Modeling
Journal of Documentation, Emerald Group Publishing,