There are at least 4 types of test plan documentation, which are needed for any software testing project. Depending on the project, cooperation and consistency in the work of team members, some test plans can be removed.
Main/Project test plan
The main test plan primarily consolidates and makes it possible to communicate for all participants of the project. It is the most important part of the software test plan. This document may include such parcels as test strategies, risks, priorities, assessments, resource applications, and others.
Acceptance test plan
It is based on customer needs and is used to check whether a performed work meets the requirements of the clients. Acceptance test cases are an aid to the application; they are designed to assist in determining whether the application should go into production.
System test plan
Integration testing ensures that different parts of the system cooperate properly with each other and exchange data between themselves in a right way.
It is basically a part of the developers testing. In unit testing we check each part of the project separately. For example, the developer can test the function of sorting separately rather than to perform comprehensive check.