What is the Performance Testing Life Cycle (PTLC)?

Performance testing is the non-functional testing of software or an application. The rigorous process of carrying out this type of QA testing via step-by-step procedure is called the Performance Testing Life Cycle (PTLC). Performance Testing Life Cycle mainly comprises two different kinds of testing: (i) Planning the performance testing as per the requirement, and (ii) identifying various performance bottlenecks in the software system.

In simpler terms, the Performance Testing Life Cycle refers to the systematic way of conducting non-functional testing on a software or application system to check its bottlenecks, loopholes, flaws, inadequacy, or potential risk factors. There are several reasons why PTLC is crucial in the software development life cycle. Let’s look at them in further detail.

Importance of Performance Testing Life Cycle (PTLC)

There has been a tremendous rise in the requirement for performance testing, especially over the last decade. It is because, with the rise of new IT companies or startups, stakeholders are concerned about whether or not the software system can handle a certain amount of load. Such concerns have made it evident that the software life cycle not only requires constant monitoring but also requires a systematic process of testing its performance under various load conditions. It not only ensures the software is built without errors but also guarantees that only the top-notch technology is released into the market for end-users. Therefore, having a performance testing life cycle is crucial for every software development life cycle process.

Breakdown of the Performance Testing Life Cycle Phases:

Performance testing life cycle, as mentioned before, is a systematic way of conducting non-functional tests on software. It comes with several stages and phases, as discussed below:

1. Planning Phase

The very first step to building an effective Performance Testing Life Cycle is to start with the right planning. Planning indicates creating a road map to conduct several non-functional tests on software to review its performance factor. 

Purpose: 

The purpose of planning a test execution is nothing but to ensure that everything runs smoothly. A detailed PTLC will comprise practical test goals, expected results, accurate strategies, and aligned support from other teams, and more. It can only be achieved when the planning is done based on relevant information, research, and defined objectives. 

Accountability: 

It is usually the responsibility of the Performance Testing Manager or Lead, to ensure that the planning phase is completed without errors or mistakes. 

Steps involved in the Planning Phase:

• Setting Objectives and Goals: This is done by gathering the client’s expectations about the project.
• Defining Metrics and Key Performance Indicators (KPIs): This is achieved by analyzing the project requirements.
• Identifying Testing Environment and Resources: Once the project requirements and objectives are clear Testing environments and resources are set up.
• Creating Test Plan and Strategy: Finally, the Performance Test Plan document is created with all the findings from before. 

Deliverable: 

The deliverable in this step is the Performance Test Plan document. It usually includes the details around which tests are urgently required, important, or needed to make the software robust. It is then passed on to the members of the other teams to make sure everybody is on the same page with the non-functional testing procedures. 

2. Preparation Phase

Once the Performance Test Plan is prepared, the teams work together to prepare for the tests as per the document. This step usually consists of two variables: Performance Test Design (which is the scripting part of the test) and Workload Modelling (which is test scenario building for the tests). It is the pre-execution activity that takes place right before the execution phase starts.

Purpose: 

The purpose of this preparation is basically to check whether the software is performing according to its expected behavior or not. Test designing is done via scripting, in this process, to stimulate real-life end-user behavior on the software, to generate various amounts of loads. Plus, workload modeling is done in this step to ensure expected production-like conditions are met in test execution. Another advantage of workload modeling is that it replicates performance issues detected in the live environment and reproduces them in the test environment. 

Accountability: 

This step is carried out by the performance test engineers or team members. Even performance test analyst can have their input in this step of the process. 

Steps involved in the Preparation Phase:

• Building Test Scenarios and Scripts: As mentioned above, test scenario and script building is mainly the purpose of this step in generating a Performance Testing Life Cycle. 
• Selecting Performance Testing Tools: While finalizing the performance testing scripts and scenarios, tools are also considered and finalized.
• Setting up Test Environment: This is a part of the test script and scenario-building process where the test conditions are set up through the use of codes.
• Establishing Baselines: Before moving on to the next stage of the performance testing life cycle, documents are prepared and benchmarks are set in this phase. 

Deliverable

There are two main deliverables in this step: one is performance test scripts (generating load in the form of real-world end-user behavior) and performance test scenarios (including predictable, scalable, and sustainable scenarios).

3. Execution Phase

The step followed by the preparation phase is the execution phase. In this stage, the performance tests are finally executed. 

Purpose:

The purpose of test execution is to test whether the software is responding in the expected way or not under virtually simulated scenarios. It helps verify test results against the pre-determined NFRs as well as helps generate an interim Performance Test Report. 

Accountability: 

It is the responsibility of the performance test engineer or analyst to execute the tests as per the planning documentation.

Steps involved in the Execution Phase:

• Executing Performance Tests: There is a minor stage before the final execution which comprises double checking if all the parameters of the test like disc space, test data, stability of the environment, etc. are verified. Then the tests are run one by one according to the planning procedure.
• Monitoring System Under Load: While the test is running it is important to keep an eye on important metrics like active users, transactions, throughput, error rate, error type, hits per second, and more. These metrics help understand the behavior of the system under load conditions. 
• Collecting Performance Data: Simultaneous reporting is necessary during test execution, especially if any bottleneck surfaces or is identified. 
• Identifying Performance Bottlenecks: As mentioned above, this is another vital part of the execution stage.

Deliverable:

The deliverable generated in this step is the Interim Performance Test Report.

4. Analysis Phase

The next stage in the process is the analysis of test results. It is the post-execution activity where the performance tester immediately collects the data from the execution and starts assessing them one by one. In this particular stage, bottlenecks are identified and remedies are suggested to improve the performance of the software. 

Purpose:

As mentioned above, the purpose of this step is to gather test results and analyze the performance of the software. In case of bottleneck detection, the performance tester/engineer/analyst must be in a position to offer remedies at various levels like business, application, network, etc. The analysis must take place according to some basic metrics like the Number of Users, Response Time, Transaction per second, Throughput, Errors, and more.

Accountability:

The performance tester or analyst is the one who is in charge of interpreting and evaluating the performance of software according to the results gathered.

Steps involved in the Analysis Phase:

• Analyzing Test Results: This is done through the interim test result that is curated during the test execution process.
• Identifying Performance Issues and Root Causes: Bottlenecks are identified and performance issues are highlighted. Testers in the process delve deeper into tracing the issue down to its core code structure.
• Correlating Performance Metrics: Performance metrics play a vital role here in conducting a thorough assessment of the software. Some metrics that are taken into consideration are the Number of Users, Response Time, Transaction per second, Throughput, Errors, and more.
• Prioritizing Issues: Finally, these issues are tackled with potential solutions and suggested by the performance engineer/tester. These notes or documents are then handed over to the developers’ team to further work on them to make the software error-free. 

Deliverable:

Same as the execution phase as it is the Interim Performance Test Report that is used during the analytical phase.

5. Reporting Phase

The final step in the process of the Performance Testing Life Cycle is reporting and recommendation. It is an essential step for PTLC as it gives further directions to the growth of the project. Plus, this final documentation with test results, analysis, remediations, etc. is handed over to the clients, stakeholders, or simply the project team to improve the software application. 

Purpose:

Performance Report is an important document in terms of project delivery. It consists of several important reports such as a detailed description of the performance tests, various observations and findings, identified defects, and more. It is important to determine whether the project has a GO or NO-GO signal.

Accountability:

The responsibility of preparing the final report lies on the shoulders of the performance test lead or manager. However, a performance tester or engineer is constantly sought out, and without his or her help, the report cannot be prepared.

Steps involved in the Reporting Phase:

• Documenting Test Results: As mentioned earlier, creating a detailed description of the whole performance test execution is the first step of this reporting phase.
• Generating Performance Reports: Once the tests are summarized then the tests are categorized according to various metrics, and performance reports are created. 
• Communicating Findings to Stakeholders: While the report is being handed over it is the responsibility of the performance tester or engineer to brief the stakeholders about the whole testing procedure, its observations, findings, suggestions, and more.
• Providing Recommendations for Improvement: In the end, recommendations are put across for the improvement of the project. 

Deliverable:

The final Performance Test Report is the deliverable here.

Advantage of Performance Testing Life Cycle:

Now, you may wonder, why is Performance Testing Life Cycle so important in software development. Well, the answer is simple. It offers a great deal of benefits to the project itself. Some of these are discussed below:

• Step-by-step planning: Performance Testing Life Cycle allows planning the whole test execution process systematically. It is the whole process of pre-execution, during, and post-execution that is aligned with the project objective as well as the developmental stages of software.
• Setting Benchmarks: The whole process of PTLC involves proper discussion, gathering information, and comprehending performance strategies, based on the project objectives. Inevitably, it gives a chance to set realistic goals, accurate expectations, and benchmarks for each test result from test execution.
• Monitoring Software Development: PTLC allows the most efficient way of monitoring the developments made in the process of software building. It offers various methods of interpreting a software’s growth and areas of improvement through crucial metrics required to fulfill the project goals.
• Selecting Appropriate Tools: A well-constructed PTLC can help decide on appropriate performance testing tools. Not all projects have the same requirements. Depending on the needs of the project, testers can pre-plan on the right tools, the right amount of tools, and hence an efficient approach towards performance testing.
• Verify Test Conditions: One of the steps in PTLC includes checking the efficiency of test cases, scripts, tools, scenarios, etc. beforehand, to ensure the test conditions are right, accurate, and stable to carry out performance testing on the software.
• Proper Assessment: Finally, PTLC offers the opportunity to create a proper assessment of the software, performing under various load conditions. It helps the clients or the stakeholders understand the exact progress of their project.

Conclusion:

In conclusion, PTLC is an important and integral part of the software development cycle. It gives the process of performance testing a lot of structure, and grounding and serves as a road map to the success of the whole test execution procedure.