Unifying Theory of Software Quality
Because Software is a Series of Economic Events with Responses
This document presents a conceptual framework and econometric model for understanding “software quality” as an all-encompassing measurement of effectiveness for software-intensive systems. UTSQ defines Software Quality as a measure of the actual economic returns compared to the expected economic returns a firm experiences from implementing a software intensive product.
UTSQ develops econometric return models for both the user and the system developer. These models provide insight into the developer’s optimal resource allocations. In addition, the paper introduces management heuristics derived from the new framework, provides a roadmap for further research, and establishes the base concepts for development of an improved support services infrastructure.
Chapter 1: Economic Quality
The UTSQ moves the concept of quality for software intensive products beyond the issue of software defects. UTSQ focuses on economic return to the User. Quality is defined and measured as providing the expected economic return. Bug free software can fail to meet the User's expected return. While pioneering software that is very buggy can far exceed expected returns.
Chapter 2: Brand or Product
Chapter 3: User-Centric Model
Chapter 4: Application Domain
This chapter presents the application domain concept and introduces tasks. Tasks are at the core of the UTSQ model and are further developed in each of the following chapters where the concepts of user value, cost, return, and risk are addressed. The domain concept provides the mechanism for establishing the full set of tasks that users perceive as valuable and related. It is from this universal set that each brand draws the tasks it will address.
Chapter 5: The Brand
In a software-intensive system one aspect of the brand is the software component of the system. This is the easiest aspect of the brand to identify. It is defined by the tasks that can be addressed by using the features of the software. In the UTSQ model this determines the value of the system for a user.
Other aspects of the brand are the less visible components: ease of use, knowledge infusion capabilities, etc. As the UTSQ is presented in the following chapters it will show that these less visible components affect costs and risks.
Chapter 6: A Task and Its Value
This chapter discusses how a user derives value from a Brand. First the fixed benefit concept for a Task is established. Next the value of the Brand, for a user, is defined as the accumulation of the value the user ascribes to each Task addressed by the Brand.
This chapter presents task value as established by the user/task coupling. This is a micro approach to establishing value others [Tassey02, page 3-6] have taken a macro approach (explain what the macro would look like). It builds the value at the lowest operational level by user by task. It is at this level of detail that information can lead to action, for the user and the developer. This is the core premise of UTSQ
Chapter 7: Brand Value to a User
Users select a brand based on the economic return they expect to realize from it. Each task addressed by the brand, if used, creates value for the user. At any point in time, a brand has a specific value to a user based on which functionality is used to accomplish a goal. Or, the manufacturer may adjust the value by adding more tasks or make existing tasks better. The value of a brand, for a specific user, is defined as that user’s value for each of the tasks the brand addresses. Brand value – as are all value determinations in the UTSQ – is established for a specific time period. Over time the user may adjust the value of specific tasks and/or the brand may modify the tasks addressed.