---
title: "Conventional waterfall model"
subject: "ICT Project Management"
chapter: 4
key: "semester_7/ict_project_management:waterfall-model"
source: https://www.bctengineer.com/q/semester_7/ict_project_management/waterfall-model
site: BCT Engineering
---

# Conventional waterfall model

ICT Project Management · Chapter 4: Project Management

- Asked in: year not given
- Video: [Waterfall Model 🔥🔥](https://www.youtube.com/watch?v=PP3g6fp9oMY) — Perfect Computer Engineer
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_7/ict_project_management/waterfall-model
- Whole chapter: https://www.bctengineer.com/md/semester_7/ict_project_management/chapter-4

## Question

What do you mean by conventional waterfall model? Explain it in detail.

## Short answer

The conventional waterfall model is a linear sequential process where each phase must be completed before the next. Phases are requirements, design, implementation, testing, deployment and maintenance. It is simple and predictable but inflexible to changes and shows working software late.

## Answer

The **conventional waterfall model** is a linear sequential software development model in which the project moves through phases in order, and each phase must be completed and approved before the next begins. The flow goes downward like a waterfall. It was described by Winston Royce in 1970 and is a predictive life cycle.

```text
Requirements
     |
     v
   Design
     |
     v
 Implementation
     |
     v
   Testing
     |
     v
 Deployment
     |
     v
 Maintenance
```

#### Phases
1. **Requirements analysis**: all requirements are collected and documented (SRS).
2. **System design**: architecture, database, interface design.
3. **Implementation**: coding of units and unit testing.
4. **Integration and testing**: system and acceptance testing.
5. **Deployment**: delivery to customer, installation and training.
6. **Maintenance**: bug fixes, enhancements.

Each phase produces documents, which are reviewed and signed off.

#### Advantages
- Simple and easy to understand and manage.
- Clear milestones, deliverables and documentation.
- Good for projects with stable, well-understood requirements.
- Easy to estimate and schedule.

#### Disadvantages
- Not flexible: changing requirements are costly.
- Working software is seen only late in the project.
- High risk and uncertainty if requirements are wrong.
- Testing occurs late; problems are found late.
- Poor for long, complex or evolving projects.

#### When to use
Small to medium projects with fixed requirements, such as payroll systems, or regulated environments where documentation is mandatory.

Modified versions allow feedback to the previous phase (**waterfall with feedback**) and the **V-model** adds testing activities for each phase.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. What is the key rule of the conventional waterfall model?
   A. Phases are repeated in short cycles
   B. Coding and requirements run in parallel
   C. Each phase must be completed and approved before the next begins
   D. Working software is released every few weeks
   Answer: C. Waterfall is linear and sequential, with sign-off at each phase. (Key point: Basic principle)

2. Why is waterfall risky when requirements are wrong?
   A. It requires constant customer presence
   B. Working software and testing come late, so problems are found late
   C. It has no documentation
   D. Testing is done too frequently
   Answer: B. Because testing and working software come late, errors in requirements surface late and are costly. (Key point: Disadvantage)

3. Which project suits waterfall best?
   A. A payroll system with fixed, well-understood requirements
   B. A start-up app with changing features
   C. A research prototype with unknown needs
   D. A product relying on daily user feedback
   Answer: A. Waterfall fits stable requirements and regulated, documentation-heavy settings. (Key point: When to use)

4. Which variant adds a testing activity corresponding to each phase?
   A. Waterfall with feedback
   B. Spiral model
   C. Kanban
   D. V-model
   Answer: D. The V-model pairs each development phase with testing, while waterfall with feedback allows returning to the previous phase. (Key point: Variants)

## Related in ICT Project Management

- [Project life cycles in detail](https://www.bctengineer.com/question.md?key=semester_7%2Fict_project_management%3Aproject-life-cycles) — ICT Project Management, chapter 4
- [Iterative and incremental model](https://www.bctengineer.com/question.md?key=semester_7%2Fict_project_management%3Aiterative-incremental-model) — ICT Project Management, chapter 4
- [Agile model](https://www.bctengineer.com/question.md?key=semester_7%2Fict_project_management%3Aagile-model) — ICT Project Management, chapter 4
- [Lean model](https://www.bctengineer.com/question.md?key=semester_7%2Fict_project_management%3Alean-model) — ICT Project Management, chapter 4
- [Project management maturity model](https://www.bctengineer.com/question.md?key=semester_7%2Fict_project_management%3Apm-maturity-model) — ICT Project Management, chapter 10

## Related in other subjects

- [Waterfall model: advantages and limitations](https://www.bctengineer.com/question.md?key=semester_5%2Fsoftware_engineering%3Awaterfall-limitations) — Software Engineering, chapter 1
- [Waterfall versus spiral; user participation](https://www.bctengineer.com/question.md?key=semester_5%2Fsoftware_engineering%3Awaterfall-vs-spiral) — Software Engineering, chapter 1
- [Software reliability; waterfall vs prototyping; embedded software](https://www.bctengineer.com/question.md?key=semester_5%2Finstrumentation_ii%3Asw-reliability-models-embedded) — Instrumentation II, chapter 9
- [Software runaways; waterfall and prototyping inside spiral](https://www.bctengineer.com/question.md?key=semester_5%2Fsoftware_engineering%3Asoftware-runaways-spiral) — Software Engineering, chapter 1