Which is cheaper, cost of quality or cost of poor quality?

Although the quality control is not part of the golden triangle (scope, time, and cost), but poor quality due to lack of quality control will cause a rework which will increase the project cost and could the schedule if the task was on the critical path.

Before thinking of correcting a problem, we should think why we could not prevent this problem in the first place. In the construction projects, the quality of the work packages are proactively planned by creating a method statement for different work packages and get the consultant and/or the client approval before starting the physical works. Method statement describe how the work package will be executed and what the prevention and correction actions to be taken.

Although, the prevention strategy could prevent most of the quality problems, but problems will happen, we cannot avoid them completely. (Wysocki 2012, p612) identified some Process Improvement Tools, which help identifying the problems and find solution accordingly as per the following tools list:

• “Fishbone diagrams and Root Cause Analysis
• Control charts
• Flowcharting
• Histograms
• Pareto analysis
• Run charts
• Scatter diagrams
• Statistical sampling
• Inspection
• Approved change requests review
• Force field analysis”

Histograms are very common process improvement tool, understood by most of project management team, and easy to classify data and select the problem cause factors for further investigation. Therefore, I would select this tool as a preliminary tool to identify quality problem, and the roost cause analysis as the detailed tool to find out the root cause of the problem.