Post 195 –by Gautam Shah
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 providers as a result have a 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.
From WW-II, and even before that vast majority of buildings (plants, products, systems) were procured using detailed design prescriptions. These contained specifications, standards, manufacturing drawings, processes, inspection procedures, etc. From 1964 and chiefly from 1993 committees of US Department of Defence proposed that objective Performance standards be offered. It is an accurate statement of the needs or performance expected of an entity and ways how that will be assessed.
Performance specifications, unlike the Design specifications (item specifications) do not prescribe the means or methods for achieving the results, or creating a product. Design specifications exactly define the quality of raw materials, processes to convert the raw materials into a deliverable product. The suppliers or vendors have no freedom to choose any other (even if better and economic) materials and methods. Products created with design specifications create a huge liability as the owner-designer, are responsible for ‘design and related omissions, errors, and deficiencies in the specifications and drawings’.
Performance specifications define the functional requirements for the product, the environment in which it must operate, and the interface and interchangeability requirements. 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?
Performance specifications state the requirements in terms of the results to be achieved and provide criteria for verifying the compliance.
〉 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.
〉 Restrictions in Performance Specifications: Performance specifications must not limit a provider to specific materials, processes (including quality of man power or equipments), parts, etc. One can, however, prohibit certain materials, processes, or parts when authorities have declared quality, reliability, or safety concerns such materials, technics 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.
〉 Structural, Architectural and Interior Design jobs and Performance Specifications: 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. 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 inter-portability.
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.