Explain the differences between SDLC and STLC?

SDLC (software development life cycle) and STLC (software testing life cycle) are two one of the most important cycles in the development of any software system or application. There is much confusion about these two topics and often characteristics of one are mistaken for the other. This article seeks to make the differences between the two confusing concepts clear.

DIFFERENCES BETWEEN SDLC AND STLC

DIFFERENCE #1:
- The systems development life cycle is one of the major concepts in the field of information systems, software and systems engineering, that one needs to understand really well.
- It can be thought of as a process following which the creation or alteration of the information systems, methodologies and other methods takes place.
- It is a cycle that is followed to keep the development of a software system or application on track.
- On the other hand, software testing life cycle is an integral part of the software development life cycle and takes care of the software testing activities.

DIFFERENCE #2:
- All these development and testing processes are not just one single activity.
- They comprise of many constituent activities that are employed for multiple tasks.
- The software development life cycle is comprised many types of different methodologies for software development.
- Usually these software development methodologies together constitute the framework for the software system or application through which the entire development process can be planned and controlled.
- In contrast to the software development life cycle, software testing life cycle is comprised of the activities for testing and certifying the final software product.

DIFFERENCE #3:
- The software development life cycle constitutes the following processes:
(a) Analysis
(b) Design
(c) Implementation
(d) Testing and
(e) Evaluation
- The software testing life cycle constitutes the following processes:
(a) Requirement analysis
(b) Test analysis
(c) Test case development
(d) Environment set up
(e) Test execution
(f) Test cycle closure
Each of the above mentioned processes under software testing life cycle is provided with an entry criteria as well as exit criteria.

DIFFERENCE #4:
- The control of the software development life cycle is taken by the system analyst and is employed for the creation of an information system.
- This cycle also involves other activities like training, validation and stake holder ownership.
- The SDLC takes care of the quality of the software system under development and ensures that it is always maintained at a high level and also that all the user expectations are satisfied.
- It also makes sure that the project is completed with a stipulated period of time as well as budget.
- Similarly the STLC takes care of the successful completion of the software testing.

DIFFERENCE #5:
- The phase of requirements gathering in software development life cycle can be compared with the requirement analysis in the software testing life cycle.

DIFFERENCE #6:
Various methodologies have been designed to implement software development life cycle like:
(a) Spiral
(b) Water fall
(c) Agile software development
(d) Synchronize and stabilize
(e) Rapid prototyping
(f) Incremental etc.
The software testing life cycle is implemented only in two ways i.e., either manually or through automation.

DIFFERENCE #7:
- The software development life cycle is managed by the system and on the other hand, the software testing life cycle is managed by the project manager.
- He/ she is the one who decides the time period for the completion of testing and allots the budget.
- The following aspects are also identified:
(a) Scope of testing
(b) Approach to be followed
(c) Associated risks
(d) Resources
(e) Time schedule

These were some of the basic differences between the SDLC and STLC. Though having many different aspects, these two cycles have many things in common.