A software process (also known as software methodology) is a set of related activities that leads to the production of the software. These activities may involve the development of the software from the scratch, or, modifying an existing system.
Any software process must include the following four activities:
- Software specification (or requirements engineering): Define the main functionalities of the software and the constrains around them.
- Software design and implementation: The software is to be designed and programmed.
- Software verification and validation: The software must conforms to its specification and meets the customer needs.
- Software evolution (software maintenance): The software is being modified to meet customer and market requirements changes.
In practice, they include sub-activities such as requirements validation, architectural design, unit testing, etc.
There are also supporting activities such as configuration and change management, quality assurance, project management, user experience.
Along with other activities aim to improve the above activities by introducing new techniques, tools, following the best practice, process standardization (so the diversity of software processes is reduced), etc.
When we talk about a process, we usually talk about the activities in it. However, a process also includes the process description, which includes:
- Products: The outcomes of an activity. For example, the outcome of architectural design maybe a model for the software architecture.
- Roles: The responsibilities of the people involved in the process. For example, the project manager, programmer, etc.
- Pre and post conditions: The conditions that must be true before and after an activity. For example, the pre-condition of the architectural design is the requirements have been approved by the customer, while the post condition is the diagrams describing the architectural have been reviewed.
Software process is complex, it relies on making decisions. There’s no ideal process and most organizations have developed their own software process.
For example, an organization works on critical systems has a very structured process, while with business systems, with rapidly changing requirements, a less formal, flexible process is likely to be more effective.