Types
Unit Testing is the name given to testing normally carried out on specific pieces of program code by a computer programmer during system development or to the tests performed during the early stages of implementing the system by the functional consultants and/or other designated project staff on a specific item of software functionality to ensure that it performs as required. This may also be referred to as Module Testing although there can be contextual differences here - e.g. unit testing could be performed on a single function with a functional module, depending on the scale of the application.
System or Functionality Testing provides a means of testing a process or procedure 'end to end' across the system, i.e. could be viewed as checking how well the individual unit tests hang together as a coherent process. On some small applications therefore these may be one and the same. Depending on the structure of the system, system testing may be the same as module testing if there are not multiple modules in use. In larger systems, however, this is likely to cross over multiple modules triggering different functions and hence this type of testing is sometimes referred to as Lifecycle Testing.
It is designed to ensure that the software functionality supports the business processes and that data integrity is maintained between the various modules or elements of the system. During this type of testing, no provisions are made specifically to measure capacity or performance capabilities, and users should record the results for each of their normal transactions and processes, and bring to the attention of the functional and technical consultants those for which the results are different to those expected.
System/functionality testing can be further broken down as:
Each user involved in the System/Functionality Testing phase should be asked to document their findings in accordance with the organisation's project procedures and confirm whether the software functionality supports the business processes and that data integrity is maintained between the various modules/elements of the system.
Where unexpected results have been reported and recorded during this phase, the relevant functional and technical consultants and/or other designated project personnel should investigate errors occurring within the system and correct them whenever possible.
Integration or Interface Testing is a specific application of either or both of the two types listed above, depending on the functionality being tested. This likely involves a heavier technical slant as it will tend to involve 'back end' system work like operating Application Programme Interfaces (APIs) to transfer data between modules and/or systems, together with detailed analysis from the functional staff to verify that data passes between the modules/systems as expected and triggers related functions as appropriate.
