Prototyping in industrial software projects:

Abstract

In many engineering disciplines, prototyping is a technique employed mainly to improve the predictability of new projects involving risks. Prototyping has been adopted as a technique in software engineering for similar reasons. However, there is little documented experience with the use of prototyping in industrial software production. The following report aims to fill this gap by presenting case studies of industrial software projects explicitly using prototyping.The five projects selected for examination range from a large-scale project in the order of 240 person-years to a small 2-person-year project. The developer teams involved range from DP departments of large industrial corporations to small-to-medium-sized software manufacturers.The report closes with an analysis of the benefits and limitations of prototyping.Prototyping is by no means a new concept. In mechanical and civil engineering, prototyping is a technique used routinely to improve the predictability of new projects that involve risk. Prototyping has been adopted as a technique in software engineering for similar reasons. 0959-3845/92/$03.50

Reported effects of rapid prototyping on industrial software quality

“…Ford and Marlin state that prototyping "allows early assessment of the efficiency of techniques [FM82]. Overall, seven cases (from six sources) cite improvement in design quality [Hek87,CB85,FM82,Bar89,A8,Kie91], while five sources observe deterioration [BGS84,CB85,Tam82,A9,A10]. Among evolutionary prototyping cases, an equal number reported better and worse design quality.…”

“…Some sources report that keep-it prototyping can result in a system with a less coherent design and more difficult integration (although [Kie91] specifically observes improved integration with prototyping). This negative effect can contribute to project failure [CB85] and can impact successful projects [BGS84].…”

“…Of 34 cases, six can be considered substantial (at least 100,000 lines of source code) [AB90,Hek87,Tam82,Mar90,Kie91,A9], and another nine are medium-sized [Gom83, BJK + 89, CB85, A1, A4, Zel80, GCG + 89, Bar89]. We used the descriptions given in the case study reports to distinguish between medium and small projects.…”

“…Only seven authors insist that prototypes be discarded. Six of the case studies [AB90,Hek87,Tam82,Mar90,Kie91,A9] represent successful keep-it prototyping on substantial software projects. On small projects, several sources suggest that keep-it prototyping is essential.…”

“…Users are more comfortable reacting to a prototype than reading a "boring" [GS81,GHPS79,Kie91] abstract written specification. No sources indicate that software produced via rapid prototyping was more difficult to use.…”