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Section 3: Software Development as a Process

Overview

Teaching: 5 min
Exercises: 0 min
Questions
  • How can we design and write ‘good’ software that meets its goals and requirements?

Objectives
  • Describe the differences between writing code and engineering software.

  • Define the fundamental stages in a software development process.

  • List the benefits of following a process of software development.

In this section, we will take a step back from coding development practices and tools and look at the bigger picture of software as a process of development.

“If you fail to plan, you are planning to fail.” - Benjamin Franklin

Software design and architecture

Writing Code vs Engineering Software

Traditionally in academia, software - and the process of writing it - is often seen as a necessary but throwaway artefact in research. For example, there may be research questions (for a given research project), code is created to answer those questions, the code is run over some data and analysed, and finally a publication is written based on those results. These steps are often taken informally.

The terms programming (or even coding) and software engineering are often used interchangeably. They are not. Programmers or coders tend to focus on one part of the software development process: implementation, more than any other. In academic research, often they are writing software for themselves - they are their own stakeholders. And ideally, they are writing software from a design, that fulfils a research goal to publish research papers.

Someone who is engineering software, on the other hand takes a wider view:

The Software Development Process

The typical stages of a software development process can be categorised as follows:

The process of following these stages, particularly when undertaken in this order, is referred to as the waterfall model of software development: each stage’s outputs flow into the next stage sequentially.

Whether projects or people that develop software are aware of them or not, these stages are followed implicitly or explicitly in every software project. What is required for a project (during requirements gathering) is always considered, for example, even if it isn’t explored sufficiently or well understood.

Following a process of development offers some major benefits:

In this section we will place the actual writing of software (implementation) within the context of the typical software development process:

Key Points

  • Software engineering takes a wider view of software development beyond programming (or coding).

  • Ensuring requirements are sufficiently captured is critical to the success of any project.

  • Following a process makes development predictable, can save time, and helps ensure each stage of development is given sufficient consideration before proceeding to the next.