Prototype — Purpose and Throwaway Risk

(1) Non-functional requirements ignored during prototyping cannot be retrofitted

(2) Rapid change during development means the prototype is undocumented — only the prototype code exists as the design specification

(3) The prototype structure has degraded through rapid change, making it difficult and expensive to maintain

(4) Organisational quality standards are normally relaxed for prototype development

Explanation

Delivering a throwaway prototype as the final system is unwise because: non-functional requirements were ignored and cannot be easily added; the prototype is undocumented; its structure has degraded; and quality standards were relaxed. Cost of building is not a stated reason.