Quality Control Process
Quality control process monitors and controls project quality and associated change management. The process of monitoring and recording results pertaining to quality activities is known as performing quality control.
Quality control activities identify causes of poor process or product quality and recommend actions to address or eliminate the issues.
Activities that control quality can take the form of preventive measures that limit risk by getting in front of potential issues. As a project manager, you can’t take anything for granted with regard to process workflows and gaining anticipated results. Instead, you should work to consider all possible activities that may provide for enhancements, optimization, or simply cleaner delivery.
Inspection activities can serve to promote quality. Some examples of inspection are: source inspections of purchased goods and inspections of raw materials; acceptance testing; product and process service audits; test equipment calibration; and rework reviews that analyse items that required revision.
Quality control measurements are the expected results of the quality metrics. Project managers and their team use quality control measurements to analyse and evaluate the quality of the deliverables and various processes.
Tools of Quality Control
- Attribute Sampling
Attribute sampling and variable sampling are useful inspection methods used by project managers. Attribute sampling is a very common statistical method used to test effectiveness of controls and determine the rate of conformance to project specifications. The findings of attribute sampling deliver a statistical basis for determining if quality controls are performing according to specifications and reflect conformance or non-conformance. Attribute sampling can be performed through the use of a tool known as a control chart.
2. Control Charts
Attribute control charts provide summaries of various aspects of quality that pertain to a product in a binary format; that is, conforming vs. non-conforming. Attribute control charts help provide details that may otherwise require more precise measurements or time-consuming procedures. They tend to require less subject matter expertise in the realm of statistics while at the same time support evidence of quality, or lack thereof.
3. Variable Sampling
Variable sampling – unlike attribute sampling, where the measurement is regarding conformance vs. non-conformance – relies on a continuous scale that measures a degree of conformance.
4. Tolerance Limits
Tolerance limits of a process are the limits within which the process is capable of producing parts. Tolerance limits are expressed as the process statistical mean plus or minus three
process standard deviation units. Typically, there are three situations that describe the relationship between tolerance, or natural limits, and specification limits.
5. Statistical Sampling
In addition to the above basic tools, there is Statistical Sampling, whereby a part of a population in-scope is randomly selected for quality inspection.
6. Check sheets
Sometimes referred to as tally sheet or checklists – gather data and other useful information to seek out defects and/or to ensure quality is being met.
Inputs to Quality Control Process
The following are considered to be inputs for Control Quality activities:
- Project Management Plan
- Quality metrics – Predefined metrics that are used to measure quality are applied as needed to determine the level of quality conformance at key specific milestones.
- Quality Checklists – Can be as simple as a punch list assigned to a team to ensure all required activities are assigned and have the required levels of attention scheduled. Work
- Performance data – Similar to quality metrics that provide details on the level of quality, work performance metrics provide details in regard to the units of work delivered to meet expected outcomes.
Quality Control Outputs
Quality control outputs represent the products of all quality-related activities that take place within a project. On an iterative basis, because quality activities take place throughout a project, quality planning, assurance, and control activities contribute to the project’s overall equilibrium.
Quality activities ensure that development and project management processes are aligned with project constraints. This helps ensure that project deliverables are being developed on time, according to specification, with minimal changes and within budget.
