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INF.04IT ProcessEngineering

Software Development Life Cycle (SDLC): How IT Systems are Built

A guide to the stages of software creation. Learn about SDLC, compare Waterfall and Agile models, and prepare for IT certification.

December 24, 20254 min read
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Software Development Life Cycle (SDLC)

Creating an application is more than just writing code. It is a process similar to building a house: from the foundations to the interior finishing. SDLC (Software Development Life Cycle) is a set of rules and stages that ensure a project doesn't collapse under its own weight and is delivered on time.

SDLC

A standardized process for software development that includes planning, designing, creating, testing, and deploying information systems.

Project Creation Stages in Practice

Every professional project goes through the same steps. Skipping any of them is almost a guarantee of future errors.

Phase 1

Analysis and Planning

Gathering requirements from the client. We determine what the system should do and if we have the budget.

Phase 2

Design

Creating the architecture, database schemas, and interface looks (UI/UX).

Phase 3

Implementation

The main stage: developers write the code based on the previously prepared designs.

Phase 4

Testing

Testers look for bugs and ensure the application meets all client expectations.

Phase 5

Deployment and Maintenance

Launching the system for users and fixing bugs reported after the release.

Development Models: Waterfall vs Agile

How a team moves through the above stages depends on the chosen work model. This is a key topic for technical exams.

CechaFeatureWaterfall Model
StructureRigid, linear (step-by-step)Flexible, iterative (loops)
ChangesVery difficult to implementWelcome at any time
Final ResultVisible only at the very end of the projectDelivered in parts (sprints)

Common Mistakes and Pitfalls

Starting coding too early

Starting to write code without a thorough design is the most common mistake. It leads to the necessity of rewriting large parts of the app after a few weeks.

Missing the testing phase

Saving time on testing is just an illusion. A bug found by a client after deployment costs 100 times more than one detected by a tester inside the company.

Example: Planning Shift in Agile

See how the approach to a task differs depending on the work model:

Before
1Plan: Build the entire online store in 8 months (Waterfall).
After
1Sprint 1: Login. Sprint 2: Product list. Sprint 3: Cart (Agile).

Pro Tips

Build an MVP (Minimum Viable Product)

Instead of building a perfect system for a year, build the simplest working version and show it to users. You will find out much faster if you are heading in the right direction.

Project Startup Checklist

What do you need to know before starting?

0/4

Quiz: Check your knowledge

Which SDLC stage handles the creation of the physical database structure?

SDLC Process Diagram

What next?

  • Learn more about Scrum methodology and working in short sprints.
  • Familiarize yourself with User Stories for describing tasks.
  • Check how User Acceptance Testing (UAT) works.
  • Read about the System Analyst's role in the SDLC process.
  • Review INF.04 exam papers for questions on development models.

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