SDLC & STLC

STLC – Software Testing Life Cycle

• Preparation of Testing Project Plan which includes Test Strategy.
• Preparation of Test Scripts which contains Test Scenarios.
• Preparation of Testing Bed. i.e.: Setting up the Test Environment
• Executing the Test Scripts (Automated as well as Manual Tests)..
• Defect Tracking with any bug tracking tools.
• Preparation of Test Completion Report and Test Incident Report.
• Preparation of Test Metrics for Continuous Process Improvement.

Models of SDLC & STLC

There are a number of different models for software development life cycle. One thing which all

models have in common is that at some point in the life cycle, software has to be tested. This

paper outlines some of the more commonly used software development life cycle, with particular

emphasis on the testing activities in each model.

1. V-Model

The figure shows the brief description of the V-Model kind of testing. Every phase of the STLC in

this model corresponds to some activity in the SDLC. The Requirement Analysis would

correspondingly have an acceptance testing activity at the end. The design has Integration

Testing (IT) and the System Integration Testing (SIT) and so on.

• V model is model in which testing is done parallel with development. Left side of v model, reflect development input for the corresponding testing activities.
• V model is the classic software development model. It encapsulates the steps in Verification and Validation phases for each step in the SDLC. For each phase, the subsequent phase becomes the verification (QA) phase and the corresponding testing phase in the other arm of the V becomes the validating (Testing) phase
• In the Software Development Life Cycle, both the Development activity and the testing activities start almost at the same time with the same information in their hands. The development team will apply "do-procedures" to achieve the goals and the testing team will apply "Check-procedures" to verify that. Its a parallel process and finally arrives to the product with almost no bugs or errors
  
• V-model is one of the SDLC STLC; it includes testing from the unit level to business level. That is after completing the coding tester starts testing the code by keeping the design phase documents that all the modules had been integrated or not, after that he will verify for system is according to the requirements or not, and at last he will go for business scenarios where he can validate by the customer and he can do the alpha testing and beta testing. And at last he decides to have the complete stable product.
• The V model shows the Development Cycle Stages and Maps it to Testing Cycles, but it fails to address how to start for all these test levels in parallel to development. It is a parallel activity which would give the tester the domain knowledge and perform more value added, high quality testing with greater efficiency. Also it reduces time since the test plans, test cases, test strategy are prepared during the development stage itself.

2.W-Model
From the view of testing, all of the models presented previously are deficient in various ways. The
test activities first start after the implementation:

• The connection between the various test stages and the basis for the test is not clear
• The tight link between test, debug and change tasks during the test phase is not clear

In the following, the W-model is presented. This is based on the general V-model and the
disadvantages previously mentioned are removed.
3.Waterfall Model
One of the first models for software development is the so-called waterfall-model by B.W.Boehm.
The individual phases i.e. activities that were defined here are to be found in nearly all models
proposed since. In this it was set out that each of the activities in the software development must
be completed before the next phase begins. A return in the development process was only
possible to an immediate previous phase.


In the waterfall-model, testing directly follows the implementation. By this model it was suggested that activities for testing could first be started after the implementation. Preparatory tasks for the testing were not clear. A further disadvantage is that testing, as the last activity before release, could be relatively easily shortened or omitted altogether. This, in practice, is unfortunately all too common. In this model, the expense of the removal of faults and defects found is only recognizable through a return to the implementation phase.


4.Extreme Programming Model




5.Spiral Model

In the spiral-model a cyclical and prototyping view of software development was shown. Tests
were explicitly mentioned (risk analysis, validation of requirements and of the development) and
the test phase was divided into stages. The test activities included module, integration and
acceptance tests. However, in this model the testing also follows the coding. The exception to this
is that the test plan should be constructed after the design of the system. The spiral model also
identifies no activities associated with the removal of defects