A test plan is a document describing the scope, approach, objectives, resources, and schedule of a software testing effort. It identifies the items to be tested, items not be tested, who will do the testing, the test approach followed, what will be the pass/fail criteria, training needs for team, the testing schedule etc.

Below is the detail of what information a test plan contains :

1.Test Plan Identifier : Provide unique identifier for the document.

2.Introduction : In this we provide overview of test plan with goals/objectives and with constraints if any.

3.References : List of all the related documents.

4.Test Items : List of test items (software/products) and their versions.

5.Features to be tested : List the features of the software/products to be tested.

6.Features not to be tested : List the features of the software/products not to be tested with reasons.

7.Approach : Discuss the approach to testing, with testing levels, testing types and testing methods.

8.Item Pass/Fail criteria : Specify the criteria that will be used to determine whether each test item (software/product) has passed or failed testing.

9.Suspension Criteria and Resumption Requirements : Specify criteria to be used to suspend the testing activity and Specify testing activities which must be redone when testing is resumed.

10.Test Deliverable : List test deliverable, and links to them if available, including the following:

• Test Plan (this document itself)
• Test Cases
• Test Scripts
• Defect/Enhancement Logs
• Test Reports

11.Test Environment : Specify the properties of test environment.

12.Estimate : Provide summary of test estimates (cost or effort).

13.Schedule : Provide the detailed schedule of the test.

14.Staffing and Training needs : Specify if any staffing or training is needed.

15.Responsibilities : List the responsibilities of each team/role/individual.

16.Risks : Specify all the risks identifies with mitigation plan and contingency plan of each risk.

17.Assumptions and Dependencies : List the assumptions and dependencies that have been made during the preparation of the plan.

18.Approvals : Specify the names and roles of all persons who must approve the plan.

So, when we get these much of information from a test plan then it serves as a guide to testing throughout the development . A test plan is a managerial document that has many levels differing in content and depth. We have test plans to ensure testing stages are performed to the best quality.

So, the importance of having a test plan is throughout the development and if we will have detailed test plan, then no problem will arise.