Post -by Gautam Shah
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General: Performance Specifications tell a manufacturer, vendor, supplier or
provider: What is considered to be an acceptable product? And How will the
product's acceptability be judged ? In other words performance specifications
state requirements in terms of the results to be achieved and provide
criteria for verifying the compliance. Such specifications define the functional
requirements for the product, the environment in which it must operate, and
the interface and interchangeability requirements. Performance specifications,
however, do not state means or methods for achieving the results. It allows
the supplier with freedom to not only choose but improvise materials and
methods.
Systems specifiers like a designer deal with a product or system only
occasionally and do not get frequent feedback. Whereas a system provider
(such as the supplier, manufacturer, fabricator or installer) is consistently
involved in supply field, and receives feedback from diverse sources. System
suppliers as a result has better understanding and capacity to improvise the
product. A system specifier may specify a technologically adequate system,
but a system provider offers a technologically superior and economically
most appropriate item.
A designer as a system specifier must work in close collaboration with the
markets (represented as the supplier, manufacturer, fabricator or installer,
etc.). To specify performance, ideally a system specifier and the parties
capable of submitting the proposal or bid, both must have a consensus as to
what the requirements are. But this type of neutral interaction is not possible
or desirable in Government deals. So it is desired that requirements of
performance are specified quantitatively rather than qualitatively. Qualitative
data can provide varying interpretations and cause misunderstandings, but
quantitative data is easily verifiable.
Performance and Verification: Any condition, characteristic, or capability that
must be achieved, and is essential for item to perform in the perceived
environment must be plausible and verifiable. For example, if a building is
required to withstand certain measure of an earthquake, then methods how to
verify this must be stated. Verification process is accompanied by definition of
'the extent of contractor or vendor's participation and their liability for providing
corrective solution’. Warranties offered by the vendor can to some extent
substitute the performance and verification requirements. However, very
often warranties of the vendors are restricted to their own supplies. The
warranties are also conceived like a risk management system for compensating
a fault with something 'equivalent' or money, but not the for the affectations
that occur in adjacent areas or systems.
In comparison to item or work specifications, performance specifications require
fewer references, except for standard tests, interface drawings, etc. Due to the
absence of procedures, performance specifications are less dependent.
Restrictions in Performance Specifications: Performance specifications must
not limit a provider to specific materials, processes (including quality of man
power or equipment), parts, etc. However, one can prohibit certain materials,
processes, or parts when authorities have declared quality, reliability, or safety
concerns such materials, techniques or processes, as for example
environmentally harmful technologies. Upper and/or lower performance
characteristics can only be stated as requirements, but not as goals or best
efforts.
Writing performance specifications: A System specification writer must know:
‘Which requirements are absolute or threshold requirements? Definitions of
such thresholds. All constraints governing operations or use through natural
and induced environments, interface with other systems, operator and
maintenance person's limitations, must be declared’‘.
Performance Specifications for Structural, Architectural and Interior Design
jobs: Such jobs consist mainly of industrially produced and standard
components, but their composition (fabrication, installation or siting) is a unique
phenomenon. Performance specifications at parts or components level are not
very difficult to implement. However, adopting a performance specification
strategy for large complex systems, or whole projects is a very difficult
proposition. Design professionals can overcome this problem by consciously
moving towards self-sufficient systems like plug-in modules, rather then
excessively customized products that remain one-time efforts. Performance
specifications at lower levels such as for replaceable components and
spares, should include essentials for interchangeability and interoperability.
Strategies for Creating Performance Specifications: It is very difficult to
conceive a fresh set of exclusive performance specifications. But one can
gradually and consciously reformat the traditional specifications with inclusion
of performance parameters for standard parts and components.
Resources for Performance Specifications: Many resources are available to
form performance specifications, such as: Government departments and large
corporate groups which prepare indexed descriptions of commercial items
for frequently or routinely required products. Such performance oriented
descriptions are available in a public domain through their purchase bids.
Trade associations, commercial organizations, or technical societies often
develop coordinated standard specifications, for the warranted performance
of items produced by their members. Government Departments design and
publish Model Specifications for use by their own sub departments and other
agencies. Performance specifications of well-organized departments like
defense, telecommunications, etc. can be used for further understanding of
the methodology. Market analysis as available in technical journals can show
the ranges of performance that are currently possible. Market analysis also
show the technologies involved and available alternatives.
Standard Performance Specifications: Standard performance specifications
are intended to facilitate standardization and interchangeability of common
equipment. Standard performance specifications specify product
characteristics, dimensions, matters relating to form, fit, and functions.
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