--- title: "Short note: Project quality control" subject: "Project Engineering" chapter: 4 key: "semester_7/project_engineering:quality-control-techniques-note" source: https://www.bctengineer.com/q/semester_7/project_engineering/quality-control-techniques-note site: BCT Engineering --- # Short note: Project quality control Project Engineering · Chapter 4: Project Implementation and Controlling - Asked in: 2081 Baisakh, 3 marks; 2078 Bhadra, 3 marks (asked 2 times) - Video: [6 MUST KNOW Quality Tools for your Project, from the PMBOK Guide](https://www.youtube.com/watch?v=wRLVjS4g5Ho) — David McLachlan - Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14 - Page: https://www.bctengineer.com/q/semester_7/project_engineering/quality-control-techniques-note - Whole chapter: https://www.bctengineer.com/md/semester_7/project_engineering/chapter-4 ## Question Write a short note on project quality control and its techniques. ## Short answer Project quality control uses operational activities—inspection, testing, measurement—to ensure work meets standards and correct non-conformance. Techniques include inspection and testing, statistical sampling, control charts, Pareto charts, cause-and-effect diagrams, histograms, scatter diagrams, check sheets, flow charts, and quality audits. ## Answer #### Project quality control **Quality control (QC)** is the set of operational activities used during the project to check that the work and materials meet the specified standards, to find defects early and to correct their causes. It includes inspection, testing, measurement, and taking action on non-conformance, so that the product is acceptable to the client. Main steps: set standards and acceptance limits, take samples and test, compare with standards, correct or reject, and record. #### Techniques of quality control 1. **Inspection and testing:** visual checks, measurement and laboratory/field tests (cube strength, slump, field density, bitumen content). 2. **Statistical sampling:** a small sample is tested to judge the whole lot, with acceptance limits. 3. **Control charts:** plot test results with upper and lower control limits over time to show whether the process is under control. 4. **Pareto chart:** bar chart arranging the causes of defects in order; shows the vital few causes (80/20 rule). 5. **Cause-and-effect (fishbone) diagram:** finds root causes of a defect under headings such as man, machine, material, method. 6. **Histogram:** shows the distribution of measured values. 7. **Scatter diagram:** shows the relation between two variables (water-cement ratio and strength). 8. **Check sheet and flow chart:** record defects and show process steps. 9. **Checklists and quality audits** of work stages. ## Check yourself The answer's key points as multiple-choice questions, with the correct option and why. 1. What does a Pareto chart show? A. The relation of two variables B. The distribution of measured values C. The vital few causes of defects arranged in order (80/20 rule) D. Upper and lower control limits over time Answer: C. A Pareto chart ranks defect causes to show the vital few. (Key point: Pareto chart) 2. What is the purpose of a control chart? A. Show process steps B. Record the number of defects on a form C. List root causes under man, machine, material, method D. Plot results against upper and lower control limits to show if the process is under control Answer: D. Control charts show whether the process is stable. (Key point: Control chart) 3. Which technique finds root causes under headings like man, machine, material and method? A. Histogram B. Cause-and-effect (fishbone) diagram C. Scatter diagram D. Check sheet Answer: B. The fishbone diagram traces root causes of a defect. (Key point: Fishbone) 4. What is the idea of statistical sampling in QC? A. No testing is done B. A small sample is tested to judge the whole lot, with acceptance limits C. Every unit is tested D. Only visual checks are allowed Answer: B. Sampling judges the whole lot from a small tested sample. 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