SDLC vs STLC

Updated March 6, 2023

Difference between SDLC and STLC

Need drives interest and makes it the only reason for any process to start. Later this interest drives the related resources, stakeholders, clients, CEO, managers, and development teams to run behind a successful project (here in our case is software development) closure. Money (interest) is the sole purpose behind these people’s behavior and time and brand value (will call even more crucial).

And this is where the article topic, yes, SDLC vs STLC, comes into the picture. Both SDLC vs STLC are interrelated to some extent, or one can say that one is the predecessor of others. The reason is simple if something is being developed for a purpose to serve (clients need), then it must be tested before deployment. This is the industry standards for decades and responsibility as the client has invested a huge amount of money after it.

This was the story behind the scene and leads us to the main section of the article – SDLC vs STLC. Let’s see in detail what are these SDLC vs STLC exactly are. What is the sequence of operations under each? What is the difference between SDLC and STLC? What kind of activities needed to have a successful ending?

SDLC means Software Development Life Cycle

LIFE CYCLE means a series of changes in one’s life. Either a living, non-living or any process that has some series of steps or sequence of operation. These sequences are a kind of indication that it has a definite start and endpoint. On the contrary, one can say that the given process has some sub-process into it. This is what a life cycle is. Figuring out what a life cycle really makes us move ahead in the discussion towards software development. So, SDLC means “the life cycle of a software development process”.

Regarding development models, there are no defined rules which advocates one over other or a particular model is good to go than the other (agile is an exception). Let’s see some models:

1. Waterfall Model – the oldest one
2. V- Model
3. Spiral model
4. Iterative
5. Agile – latest and most suitable to any project kind

Phases in SDLC discussion

These process can also be listed as below –

1. PLANNING – First thing first, before any physical evidence appears, there is always planning behind it. Planning comes before paperwork has started. In this phase, only the high-level details are considered from the Projects’ point of view. A dedicated group of members is behind this phase. All the pro’s and cons related to the projects are considered, and how to maximize the ROI and ways to do it also considered. Here there is lots of rework and review is done to overcome any hindrance to project success. The bottom line is before the idea is brought into reality, it should have concrete reasons to run and achieve success. Planning again depends upon the kind of outcome. If new software is building the planning will be different as the market study will be very crucial for it, but if the same software is being updated after a few years, then, in this case, there will not be any market study (as the software is a success and so there is a need for software features updates building).
2. ANALYSIS – Once the planning portion is done, then comes the analysis where the dedicated teams do several tasks before they attain a concrete solution. Here, the project’s feasibility study is done, estimation work, costing, requirement elicitation, and scheduling. The intention is clear to do a final check before the work actually starts. Suppose any shortcomings are there, then removing them by communication with the development team and the stakeholders. Find out the pros and cons.
3. DESIGN – Now the requirement is clear, and the team wants some reference before they work; the designers play a crucial role. The software will work (functionality-wise), how many screens will be there for each section, user interactivity, and every bit of details designed in this phase. Let’s say a customer asked for mobile software for flight booking, and the requirement is clear that the designers will design the screens to cover the functionalities this software will process. The designers will come up with layouts, working plans, process diagrams, pseudocodes and several other kinds of design documentation. The responsible persons will choose the best to go with.
4. CODING – at this stage, most of the major decisions have already been decided. The intention of this phase is to replicate the design works into a working piece of software. Here the developers play a prominent role, and efforts are laid to produce reusable codes. Many discussions related to a framework and the best suitable methods to create a working software are paid attention to. There are programming tools involved which are used by the team of developers, which are – Compiler, Debugger, Interpreter. I would like to bring my readers to the attention that the development of complete working software is not easy and neither small. A big chunk of work is there, so the development team break them into smaller deliverables and prioritize them as per the need or urgency (can also be rated on the basis of how crucial the functionality is, i.e. how high that particular functionality has been rated). Remember, this is the longest phase of the development cycle.
5. TESTING – In this phase comes to the STLC. This phase is all about testing the developed piece of working software before it is forwarded to the clients or the end-users. The testers perform several types of test methodology to find out any possible defects in the software.
6. MAINTENANCE – This is a kind of after-sales service. Like the way we purchase any bike or car, and after a year, there is an issue that produces any hindrance towards proper working. These kinds of issue arise time and again. Here all the bugs that arise when the client is using the software are resolved, any upgradation needed in future or enhancements if any.

STLC means SOFTWARE TESTING LIFE CYCLE

Phases in the STLC –

1. Requirement Analysis
2. Test Planning
3. Test case development
4. Environment setup
5. Test Execution
6. Test cycle closure

1. REQUIREMENT ANALYSIS – The very first step into the STLC process. It’s the part in the entire process where the QA teams get to know the requirement (means what to test) and testable requirements. To better understand the requirement, the tester can follow up with the clients (but this rarely happens, only if the testing is needed and not the development). This is a kind of chart that followed in this phase of STLC.

2. TEST PLANNING – The most crucial phase in STLC. Here every estimates and time are calculated before the testing actually starts. The result of this will test plans or strategies documentations. Once this phase is completed, the QA team can start with test case development activities. The same chart, which is drawn in the upper phase, is again used with changes.
3. TEST DEVELOPMENT – The actual development of test cases is worked after the test planning phase has been completed. Here the testing teamwork on the test cases. Not only the test cases but a complete report which contains the test data are involved and documented. Once completed, these are cross verified by peer members or QA leads. Here itself, the RTM (requirement traceability matrix) is also prepared. These documents track the requirement in both ways (means forward and backwards).
4. ENVIRONMENT SETUP – This is, in general, not practiced because the environment has already been decided during the development phase (in SDLC). In general, there does not happen any changes in the environment.
5. TEST EXECUTION – Here, the test cases are executed based on the test plans initially prepared. If the cases are ok, they are marked as PASS; otherwise, they FAIL. A complete list of bugs is prepared in this phase and forwarded to the development team to fix before the software’s final release.
6. TEST CYCLE CLOSURE – A discussion where the team decides what went right and wrong from test perspectives. Things to improve in future that can save time and effort in the right direction are discussed in this meeting. These are helpful from the development perspective.

Head To Head Comparison Between SDLC and STLC (Infographics)

Below is the top 9 difference between SDLC vs STLC

Key Differences Between SDLC and STLC

Both are popular choices in the market; let us discuss some of the major difference:

• SDLC is a Development Methodology, whereas STLC is a Testing Methodology
• Multiple different phases are combined to form SDLC, whereas Multiple testing phases or practices combine to form STLC.
• SDLC covers the entire software development cycles, whereas STLC covers the entire testing cycles
• SDLC starts with the planning phase and covers the entire development look through whereas STLC starts with Test Planning and covers every aspects or type of testing
• CEO, Senior Business Analyst, Senior Managers, and Developers are the people who look after several stages under SDLC. On the other hand, QA Lead, Test Analyst is the people who govern the ongoing process.
• SDLC starts when the actual application has not been created, but STLC starts when the actual application exists or a chunk of working software exists.
• SDLC is the superset of STLC, whereas STLC is the subset of SDLC

SDLC vs STLC Comparison Table

Let’s look at the top Comparison between SDLC vs STLC –

Conclusion

The discussion is clear regarding the SDLC vs STLC. One is the development approach, and the other is the testing approach as a whole. Though Testing comes under SDLC as one of the sections, the important thing to note is that it is a very different function that is performed. It is essential to note that STLC in under the SDLC. The concerned activities in each section are different.

Recommended Articles

This has been a guide to the top difference between SDLC vs STLC. Here we also discuss the key differences with infographics and comparison table. You may also have a look at the following articles to learn more-

1. SDLC vs Agile
2. PL SQL vs SQL
3. Agile vs DevOps
4. SDLC Methodologies