---
title: "Differentiate quality control and assurance"
subject: "Project Engineering"
chapter: 4
key: "semester_7/project_engineering:qa-vs-qc-differentiate"
source: https://www.bctengineer.com/q/semester_7/project_engineering/qa-vs-qc-differentiate
site: BCT Engineering
---

# Differentiate quality control and assurance

Project Engineering · Chapter 4: Project Implementation and Controlling

- Asked in: 2082 Baisakh, 4 marks
- Video: [Quality Assurance vs Quality Control Explained: QA vs QC Made Simple](https://www.youtube.com/watch?v=91PRprVo1LE) — PM Aspirant
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_7/project_engineering/qa-vs-qc-differentiate
- Whole chapter: https://www.bctengineer.com/md/semester_7/project_engineering/chapter-4

## Question

Differentiate between quality control and quality assurance.

## Short answer

QA is a proactive, process-focused system to prevent defects through quality plans, audits, and training. QC is a reactive, product-focused set of inspection and testing techniques to detect defects. QA builds quality into the process; QC checks quality in the product.

## Answer

**Quality assurance (QA)** is the planned and systematic set of activities in the process that gives confidence that quality requirements will be fulfilled. **Quality control (QC)** is the set of operational techniques used to inspect and test the product to check that it meets the requirement.

| Basis | Quality assurance (QA) | Quality control (QC) |
|---|---|---|
| Meaning | Planned system of activities to give confidence that quality requirements will be met | Operational techniques to check that the work meets the requirement |
| Focus | Process; prevents defects | Product; detects defects |
| Nature | Proactive | Reactive |
| When | Before and during the work | During and after the work |
| Responsibility | Whole organisation and management | Site and testing team |
| Tools | Quality plan, audits, procedures, training | Inspection, tests (cube test, slump, compaction), checklists |
| Example | Setting the method statement and approving materials | Testing concrete cubes at 7 and 28 days |

In short, QA is *building quality into the process* and QC is *checking quality in the product*.

## Check yourself

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

1. What is the focus of QA and of QC?
   A. QA: product; QC: process
   B. QA: process; QC: product
   C. Both: product only
   D. Both: process only
   Answer: B. QA builds quality into the process and prevents defects; QC checks the product and detects defects. (Key point: Focus)

2. Which pairing of nature is correct?
   A. QA is reactive, QC is proactive
   B. Both are reactive
   C. QA is proactive, QC is reactive
   D. Both are proactive
   Answer: C. QA acts before defects occur (proactive); QC finds defects that already exist (reactive). (Key point: Nature)

3. Who is responsible for QA and for QC?
   A. QA: whole organisation and management; QC: site and testing team
   B. QA: testing team; QC: top management
   C. Both: only the client
   D. Both: only labourers
   Answer: A. QA is organisation-wide and managed; QC is carried out by the site and testing team. (Key point: Responsibility)

4. Which pair of examples is correct?
   A. QA: testing cubes; QC: approving method statements
   B. QA: setting method statement and approving materials; QC: testing cubes at 7 and 28 days
   C. QA: slump test; QC: audits
   D. QA: compaction test; QC: training
   Answer: B. Method statements and material approval are QA; cube, slump and compaction tests are QC. (Key point: Examples)

## Related in Project Engineering

- [Monitoring vs evaluation; quality control tools](https://www.bctengineer.com/question.md?key=semester_7%2Fproject_engineering%3Amonitoring-vs-evaluation-quality-tools) — Project Engineering, chapter 4
- [Control cycle; quality control factors](https://www.bctengineer.com/question.md?key=semester_7%2Fproject_engineering%3Acontrol-cycle-quality-control-factors) — Project Engineering, chapter 4, asked 2×
- [Short note: Project quality control](https://www.bctengineer.com/question.md?key=semester_7%2Fproject_engineering%3Aquality-control-techniques-note) — Project Engineering, chapter 4, asked 2×
- [Monitoring and quality, cost, schedule control](https://www.bctengineer.com/question.md?key=semester_7%2Fproject_engineering%3Amonitoring-quality-cost-schedule-control) — Project Engineering, chapter 4
- [Closed and open control; quality cost](https://www.bctengineer.com/question.md?key=semester_7%2Fproject_engineering%3Aclosed-open-control-quality-cost) — Project Engineering, chapter 4
- [QA vs QC; types of cost of quality](https://www.bctengineer.com/question.md?key=semester_7%2Fproject_engineering%3Aqa-vs-qc-cost-of-quality) — Project Engineering, chapter 4, asked 2×

## Related in other subjects

- [Software quality assurance](https://www.bctengineer.com/question.md?key=semester_5%2Fsoftware_engineering%3Asqa-note) — Software Engineering, chapter 9
- [Quality assurance](https://www.bctengineer.com/question.md?key=semester_7%2Fict_project_management%3Aquality-assurance) — ICT Project Management, chapter 10
- [Quality control of concrete at site](https://www.bctengineer.com/question.md?key=semester_5%2Fconcrete_technology_and_masonry_structure%3Aquality-control-at-site) — Concrete Technology and Masonry Structure, chapter 5, asked 11×
- [Asphalt concrete construction and quality control](https://www.bctengineer.com/question.md?key=semester_7%2Ftransportation_engineering_ii%3Aasphalt-concrete-construction) — Transportation Engineering II, chapter 3, asked 5×