Software Development Life Cycle Examples in CS Thinking
Start with the recap, study the fully worked examples, then use the practice problems to check your understanding of Software Development Life Cycle.
This page combines explanation, solved examples, and follow-up practice so you can move from recognition to confident problem-solving in CS Thinking.
Concept Recap
The structured process of planning, creating, testing, deploying, and maintaining software, typically following phases: requirements gathering, design, implementation (coding), testing, deployment, and maintenance. Different methodologies (waterfall, agile, spiral) organize these phases differently.
Building software is like building a house — you plan, design, build, inspect, and maintain. Skipping steps leads to problems.
Read the full concept explanation →How to Use These Examples
- Read the first worked example with the solution open so the structure is clear.
- Try the practice problems before revealing each solution.
- Use the related concepts and background knowledge badges if you feel stuck.
What to Focus On
Core idea: The SDLC provides structure so that complex software can be built reliably. Different models (waterfall, agile, spiral) emphasize different approaches.
Common stuck point: Agile doesn't mean 'no planning.' It means shorter cycles with frequent feedback, not chaos.
Sense of Study hint: When studying the SDLC, compare two models: Waterfall (complete each phase before moving to the next, good for stable requirements) and Agile (short cycles called sprints, each producing a working increment, good for evolving requirements). Both follow the same phases but in different rhythms.
Worked Examples
Example 1
easyList the main stages of the Software Development Life Cycle (SDLC) in order.
Answer
Analysis → Design → Implementation → Testing → Deployment → Maintenance.
First step
1
Step 1: Analysis — understand what the client needs and gather requirements.
Full solution
- 2 Step 2: Design — plan the solution (data structures, algorithms, user interface, architecture).
- 3 Step 3: Implementation — write the code. Testing — verify it works correctly. Deployment — release to users. Maintenance — fix bugs and add features over time.
The SDLC provides a structured framework for developing software. Each stage builds on the previous one, and skipping stages often leads to costly problems later.
Example 2
mediumCompare the Waterfall and Agile approaches to software development. Give one advantage of each.
Example 3
mediumA government project has fixed requirements and strict audit trails. Recommend Waterfall or Agile and justify briefly.
Example 4
mediumA startup ships every Friday with no design docs. Name two risks.
Example 5
hardA team's velocity has dropped 30% over three sprints. Name two retrospective questions that might surface the cause.
Example 6
challengeA startup wants weekly releases AND ISO-27001 compliance. Sketch a process that satisfies both.
Practice Problems
Try these problems on your own first, then open the solution to compare your method.
Example 1
mediumA school wants a new student attendance system. For each SDLC stage, describe one specific activity that would be performed.
Example 2
hardA startup is building a new social media app with unclear requirements that will likely change. Which development methodology would you recommend and why? What risks does your choice introduce?
Example 3
easyOrder these SDLC phases: implementation, requirements, design, testing. Which comes FIRST?
Example 4
easyPut in order: requirements, design, implementation, testing, maintenance. What comes right AFTER design?
Example 5
easyWhich SDLC phase comes LAST in the typical lifecycle?
Example 6
easyWhich phase comes right BEFORE deployment in a typical lifecycle?
Example 7
easyWhich methodology organizes work into iterative sprints with frequent feedback?
Example 8
easyWhich methodology runs phases in a strict linear sequence with little backtracking?
Example 9
easyTrue or false: skipping requirements and design to start coding immediately is a recommended practice.
Example 10
easyIn which phase is a design specification primarily produced?
Example 11
mediumA team finishes coding, then users report the build solves the wrong problem. Which phase was likely skipped or rushed?
Example 12
mediumOrder fully: design, maintenance, requirements, testing, implementation. Give the correct sequence.
Example 13
mediumMid-project, a stakeholder changes a key requirement. In a healthy process, what should happen?
Example 14
mediumWhich statement about agile is correct: (a) agile means no process, (b) agile has sprints, reviews, and retrospectives?
Example 15
mediumA bug is reported one year after release. Which SDLC phase is the team operating in?
Example 16
mediumWhich phase verifies that the software meets the acceptance criteria from the spec?
Example 17
mediumIn waterfall, requirements were 'frozen' but reality changed. What is the realistic consequence?
Example 18
mediumA team writes code first, then realizes there is no test plan or acceptance criteria. Which earlier phase was skipped?
Example 19
mediumWhich SDLC phase turns the design specification into running code?
Example 20
challengeA startup expects requirements to change weekly and needs frequent user feedback. Recommend a methodology and justify in one phrase.
Example 21
challengeA safety-critical avionics system has fixed, fully-known requirements and demands heavy up-front documentation. Which model fits best and why?
Example 22
challengeA change request arrives during testing. Trace the minimal correct path back through the SDLC to ship it safely.
Example 23
easyWhich SDLC phase produces a requirements document?
Example 24
easyWhat does 'agile' emphasize that waterfall does not?
Example 25
easyWhich methodology has overlapping iterative cycles with risk analysis at each loop?
Example 26
easyTrue or false: maintenance ends as soon as the product ships.
Example 27
easyA two-week sprint produces working software at its end. Which methodology does this describe?
Example 28
mediumA team finishes deployment but no one is on call when a bug appears. Which SDLC phase did they neglect to plan?
Example 29
mediumIn Scrum, the retrospective at the end of a sprint serves what purpose?
Example 30
mediumWhich SDLC artifact captures stakeholder needs in measurable language?
Example 31
mediumMid-design, the team realizes a requirement is contradictory. What is the correct action?
Example 32
mediumWhich SDLC phase typically owns code review and unit testing?
Example 33
mediumDefine 'minimum viable product' (MVP) in one sentence.
Example 34
mediumWhich phase produces release notes and deployment scripts?
Example 35
mediumWhich testing level verifies that two modules together behave correctly?
Example 36
mediumA version-control branch is merged after passing review and CI. Which phase does this most belong to?
Example 37
hardCompare the cost of fixing a bug found in requirements vs found in production. Which is cheaper and why?
Example 38
hardA medical device firm runs a hybrid: waterfall for regulated requirements, agile for UI iteration. What is this approach called?
Example 39
hardWhat is technical debt and which SDLC phase typically accumulates it fastest?
Example 40
challengeA regulator demands traceability from each line of code to a requirement. Which SDLC artifact ties them together?
Related Concepts
Background Knowledge
These ideas may be useful before you work through the harder examples.
design specification