Software development lifecycle is a process of creating the software products. It consists of several steps which have not strict but still somehow determined order. This procedure presupposes the applying of certain methods.

There are four development models that are the most frequently used. The other ones are just the modifications of these main models.

What Are the Most Often Used Models?

• Big-Bang
• Code-and-Fix
• Waterfall
• Spiral

Each of listed models has its own pros and cons. A tester should base software testing, mobile testing or desktop application testing on the applied model. Both the development and testing processes are interrelated.

What Are the Specific Features of Big-Bang Model?

• The development procedure is not well planned and scheduled.
• The date of product release can be easily changed. It is not fixed.
• The testing process may be either skipped or just formally performed. In most cases, it is exploratory testing, as there is no well formulated product specification.
• All attention is paid to the process of code writing.

Big-Bang model is rather simple one. But no one can be pretty sure that the quality of final product will be of a high level. There is a big possibility that the product will contain a lot of bugs if testing is ignored at all.

What Are the Main Characteristics of Code-and-Fix Model?

• It is the cycled process. The developers write the code, testers check it and report the bugs, and then the developers remove the errors and make the release updates. After that, the whole procedure repeats again and again.
• The development process starts with planning and is based on some documentation.
• The tester’s and developer’s work is not coordinated. A tester may not finish checking the previous release when the new one is ready.
• This model is more suitable for the small projects.

The Waterfall model has defined procedure. It starts with the idea, then goes a thorough analysis, design determining, the development procedure itself, testing and the final production.

What Are the Core Aspects of the Waterfall Model?

• The product specification is focused on. It should be comprehensive, complete and define every part of the development process.
• Each step of software development lifecycle is detached, they are not interpenetrated.
• In most cases, there is no possibility to back up. A specialist should finish the task and only then pass on the next step.
• The checking procedure is very detailed and thorough. Every system element as well as functional aspect is controlled with the help of performance testing, load checking, unit and integration testing, etc.

According to the Spiral model, at the very beginning every step is not specified in details. In the course of development process, the needed aspects are discussed and analyzed.