The Item or Design specifications are very traditional. These are used for execution, manufacturing, fabricating, erecting, for procuring ready-made objects, and also for effecting various services. The term Design here means any scheme, as such orally conveyed, written, drawn, or otherwise implied. Design or scheme specifies constituents, processes of combining, synthesizing a coherent entity or system, method of care and handling the men, materials, machines, and the entity itself as it is being created.
Primary instinct for a human effort is to create a Recipe or Process. We think or enact the thing we desire, and then project the intentions as: 1 list of physical inputs (ingredients), 2 step by step method (time sequence), 3 list of things to do and not to do (human intervention). A fair mix of first two (aspects) can provide an object, but not a deliverable entity. It is the last aspect that helps create an occasion or situation specific working entity and with definite level of efficiency.
A recipe is a perfect example of a design specification. When a design (recipe) is specified for a product and once readied (with reasonable sincerity), a client has to pay for it even if it fails on acceptability count. As a result, writing Item or Design Requirements is never advisable, unless the specifiers have had recent experience, at designing a nearly Identical Item, and fully comprehend all aspects of the design problem.
SPECIFICATIONS FOR A DESIGNED OBJECT
A Designer prepares the Item or design specifications, (materials, procedures and conditions of origin), so that contractor or vendor can provide the stated item. In this method a contractor or vendor gets no freedom to use alternative materials or execute it differently.
If there is an uncommon item, the contractor will invariably charge more for the extraordinary effort or customization. This process does not assure that in spite of a sincere execution and diligent supervision a functional product will be delivered. The Item specifications specify ‘physical adequacy of the item while seeking a hypothetical performance’.
SPECIFICATIONS FOR SOURCING A READY-MADE OBJECT
Item specification for acquiring a ready-made object by a designer tends to be even more restrictive. The specifications either have to match the standards followed by the Industry or match some ‘super’ supplier’s specifications. Failing either of the conditions, one has to pay the extra cost of customizing a regular or standard item. In the later case the assurance nominally available for the regular or standard item are unlikely to be offered for the altered form.