Mumbai University > Information Technology > Sem 8 > Software Testing and Quality Assurance

Marks: 5M

Objectives of testing:

It does work:

1. While implementing a program unit, the programmer may want to test whether or not the unit works in normal circumstances.
2. The programmer gets much confidence if the unit works to his or her satisfaction. The same idea applies to the entire system as well - once a system has been integrated, the developers may want to test whether or not the system performs the basic functions.
3. Here, for the psychological reason, the objective of testing is to show that the system works, rather than it does not work.

It does not work:

1. Once the programmer (or the development team) is satisfied that a unit (or the system) works to a certain degree, more test are conducted with the objective of finding faults in the unit (or the system).
2. Here, the idea is to try to make the unit (or the system) fail.

Reduces the risk of failure:

1. Most of the complex software systems contain faults, which cause the system to fail from time to time.
2. This concept of failing from time to time gives rise to the notion of failure rate.
3. Thus, a high level objective of performing tests is to bring down the risk of failing to an acceptable level.

Reduce the cost of testing:

The different kinds of costs associated with a test process include:

1. The cost of designing, maintain and executing test cases
2. The cost of analysing the result of executing each test case
3. The cost of documenting the test cases
4. The cost of actually executing the system and documenting it.

Therefore, the highest level of objective of performing tests is to produce low-risk software with fewer numbers of test cases.

Difference between Validation and Verification

Issues of testing:

1. Test planning and scheduling problems often occur when there is no separate test plan, but rather highly incomplete and superficial summaries in other planning documents. Test plans are often ignored once they are written, and test case descriptions are often mistaken for overall test plans. The schedule of testing is often inadequate for the amount of testing that should be performed, especially when testing is primarily manual.

2. Stakeholder involvement and commitment problems include having the wrong testing mind-set (that the purpose of testing is to show that the software works instead of finding defects), having unrealistic testing expectations (that testing will find all of the significant defects), and having stakeholders who are inadequate committed to and supporting of the testing effort.

3. Management-related testing problems involve the impact of inadequate management. For example, management can fail to supply adequate test resources or place inappropriate external pressures one testing. There may be inadequate test-related risk management or test metrics.

4. Test organizational and professionalism problems include a lack of independence, unclear testing responsibilities, and inadequate testing expertise.

5. Test process problems often occur when testing and engineering processes are poorly integrated. Organizations sometimes take a "one-size-fits-all" approach taken to testing, regardless of the specific needs of the project. Other problems include inadequate test evaluations and inadequate test maintenance.

6. Requirements-related testing problems are related to the requirements that should be driving testing. Often, the requirements are ambiguous, missing, incomplete, incorrect, or unstable. Lower-level requirements may be improperly derived from their higher-level sources. Likewise, verification methods may be unspecified and the tracing between requirements and tests may be lacking.