2.2 Component Software Processes

As defined above, a process is the sequence of steps executed to achieve a goal. Since many different goals may have to be satisfied while developing software, multiple processes are needed. Many of these do not concern software engineering, though they do impact software development. These could be considered nonsoftware process. Business processes, social processes, and training processes are all examples of processes that come under this. These processes also affect the software development activity but are beyond the purview of software engineering.

The processes that deal with the technical and management issues of software development are collectively called the software process. As a software project will have to engineer a solution and properly manage the project, there are clearly two major components in a software process—a development process and a project management process. The development process specifies all the engineering activities that need to be performed, whereas the management process specifies how to plan and control these activities so that cost, schedule, quality, and other objectives are met. Effective development and project management processes are the key to achieving the objectives of delivering the desired software satisfying the user needs, while ensuring high productivity and quality.

During the project many products are produced which are typically composed of many items (for example, the final source code may be composed of many source files). These items keep evolving as the project proceeds, creating many versions on the way. As development processes generally do not focus on evolution and changes, to handle them another process called software configuration control process is often used. The objective of this component process is to primarily deal with managing change, so that the integrity of the products is not violated despite changes.

These three constituent processes focus on the projects and the products and can be considered as comprising the product engineering processes, as their main objective is to produce the desired product. If the software process can be viewed as a static entity, then these three component processes will suffice. However, a software process itself is a dynamic entity, as it must change to adapt to our increased understanding about software development and availability of newer technologies and tools. Due to this, a process to manage the software process is needed.

The basic objective of the process management process is to improve the software process. By improvement, we mean that the capability of the process to produce quality goods at low cost is improved. For this, the current software process is studied, frequently by studying the projects that have been done using the process. 

The whole process of understanding the current process, analyzing its properties, determining how to improve, and then affecting the improvement is dealt with by the process management process. The relationship between these major component processes is shown in Figure 2.2. These component processes are distinct not only in the type of activities performed in them, but typically also in the people who perform the activities specified by the process. In a typical project, development activities are performed by programmers, designers, testers, etc.; the project management process activities are performed by the project management; configuration control process activities are performed by a group generally called the configuration controller; and the process management process activities are performed by the software engineering process group (SEPG). 

 

Figure 2.2: Software processes.

In this book, we will focus primarily on processes relating to product engineering, particularly the development and project management processes. Much of the book discusses the different phases of a development process and the subprocesses or methodologies used for executing these phases. For the rest of the book, we will use the term software process to mean product engineering processes, unless specified otherwise.