Geometrical and statistical foundations of a three-dimensional model of software performance

This work presents the geometrical and statistical foundations of a three-dimensional model of a software project performance model called QEST (Quality factor + Economic, Social and Technical dimensions). In this model, the three dimensions taken into consideration are combined through the use of a regular tetrahedron geometrical representation of a pyramid, the sides of which represent the normalised values of each of the project dimensions being measured and the apex represents the normalised optimal target value of each project dimension. This paper presents the three geometrical concepts used for assessing project performance progress using geometrical concepts of distance, area and volume, and describes how the corresponding geometrical formulae are derived. The relative merit of each is also discussed and an analysis is included of the multiple combinations of values along the three axes which can be used to assess the respective adequacy of each in order to convey maximum information in the greatest number of instances along all the axes. (C) 1999 Elsevier Science Ltd. All rights reserved.