Applying a Functional Measurement Method: Cognitive Issues

The application of a software functional measurement method is an intellectual process carried out on a complex abstract artifact: this process includes both a mapping phase between the measurement model and the software model, and a measurement phase for the instantiation of the measurement rules to the derived mapping model. In industrial contexts, two types of difficulties often occur when measuring software: 1the software models might not be available, and, when they are, they may be incomplete and, as frequently happens, may not use the same modeling approaches and formalisms and 2applying the specific formalisms of a measurement method to a wide variety of intellectual products which are usually not fully documented can lead to problems of homogeneity (coherence) of measurement results, even among experts. The activity of mapping the functional measurement method to any type of software model, and then instantiating the specific measurement rules, in a specific context, is characteristic of an "expert task" which can itself be modeled in turn within a knowledge system. This paper explores the cognitive issues arising from these mappings, and the necessary context interpretations needed to address these issues, and then proposes an expert-system approach to tackle these cognitive issues in order to achieve consistency in the measurement results. 1 Human expertise, even in a relatively narrow domain, is often set in a broader context which involves a good deal of common-sense knowledge about the everyday world (11, p. 5). The functional size measurement method selected to investigate the feasibility of the approach is COSMICFFP, and the knowledge system to be used is Help CPR. In this paper, we present: 1 the various phases of the measurement process; 2 – cognitive issues in the application of COSMIC-FFP in the context of an organization; 3 the experimental case-based reasoning (CBR) approach proposed to address these issues; 4 some examples of the resolution of problems using a CBR-type tool within a diagnosis procedure. 1. Measurement process According to Abran et al. (3), there are four phases in the measurement process, as follows, and illustrated in Figure 1: 1Design of the measurement method; 2Measurement method application, in a specific context; 3Measurement results analysis; 4Exploitation of the measurement results, for instance in decision-making models, quality models and estimation models. 2 We replace the word "step" used in the Abran et al. article (2) by the word "phase", in order to avoid confusion with the steps of the COSMIC-FFP method..