Constructing Quality Models

Abstract

In this chapter, we introduce the concept of quality as related to conceptual models and provide two non-exclusive approaches through which a model’s quality may be assessed: how well the model allows us to achieve our purpose and how well the model can be understood or modified. Each of these is fleshed out into various quality factors, including functional ones such as correctness and robustness as well as non-functional ones, such as usability or readability. Then, we introduce the notion of modularity as a way to achieve better quality in conceptual models, using Bertrand Meyer’s influential work in software languages. We define a module as a portion of a model that exhibits high internal cohesion and low external coupling and explore five quality criteria that can help us produce more modular models: decomposability, composability, understandability, proportion and protection. Finally, the chapter closes with a discussion on the cost of quality and the need to achieve a balance between quality, time and resources.