Quality control plan

Quality control plan is a document that describes product, service or process characteristics that should be monitored in order to achieve expected result. The plan helps to increase and keep the discipline in the process, which leads to better stability and more predictable results.

Types of quality control plans

The main types of plans are:

• Process quality control plan - describes characteristics of the process
• Product/service quality control plan - describes characteristics of the product/service
• Project quality control plan - describes quality control in project management
• PDCA quality control plan - used in improvement and corrective actions to evaluate their results

Structure of the plan

There is no one standard for quality control plan, however every plan will contain several common elements. The key elements of the plan are:

• Description of object being the subject of the plan
• Responsibility and entitlements of staff
• Preliminary checks - things to check before the beginning of the process, project, etc.
• Initial checks - things to check during initialization of the process, production
• Sampling methods - during the process usually only samples should be monitored
• Final checks - things to check prior to or after finishing
• Reaction to defects - description how to react when defects are found
• Reporting (what, to whom and how often)

Sampling in quality control

Sampling can be based on agreements or internal/external standards that define acceptable quality level (AQL). The main types of sampling are:

• single-stage sampling plan,
• double-stage sampling plan,
• accept on zero,
• continuous sampling.

Sampling was described in detail in separate article.

Off-line and on-line quality control

Off-line quality control is related to prevention of failures. On-line quality control is related to real-time production. Both were described in article Quality control.

Benefits of planning quality control

The quality control takes time and gives no profits (at first sight). Therefore, it is too often skipped or reduced below reasonable level. Quality control planning helps to prevent this. Moreover, it:

• Provides a summary of our knowledge about process/product/project
• Keeps requirements visible
• Describes data used to performance evaluation
• Describes what to do in case of quality problems
• Shows the roles of the staff

Quality plan vs. quality control plan

In many publications the quality control plan is misunderstood as quality plan. Quality plan describes actions planned in order to improve quality, while quality control plan is used to only monitor whether the quality is consistent with specification.

The content of the quality plan, according to ISO 9001:2015 should consist of:

• What it is to be done,
• What resources will be required (financial, material, knowledge, etc.),
• Who will be responsible for the effects,
• When should it be finished,
• How the results will be evaluated.

Examples of Quality control plan

• Quality control plans are used in manufacturing to ensure that products meet predetermined specifications. For example, a company producing a car may have a quality control plan in place that requires the vehicle to pass certain tests such as safety, performance, and emissions tests before being released to the market.
• Quality control plans are also used in software engineering. For example, a software developer may have a quality control plan in place to ensure that the software they create meets certain standards in terms of usability, reliability, and performance.
• Quality control plans are also used in the medical industry. For example, a hospital may have a quality control plan in place that requires all medical staff to follow certain protocols in order to ensure the highest possible standard of care for patients.
• Quality control plans are also used in the hospitality industry. For example, a hotel may have a quality control plan in place to ensure that all customer service representatives are following established guidelines for customer service.

Limitations of Quality control plan

• Quality control plans may not be effective in all situations. Different processes and products may require different steps and approaches to ensure quality.
• Quality control plans can be time-consuming and costly to develop and implement, requiring significant resources and personnel.
• Quality control plans may not be effective if they are not updated regularly. Technology and processes may change, requiring updates to the plan.
• Quality control plans may not account for every possible aspect of quality assurance. Unforeseen circumstances or variations may not be anticipated or taken into account.
• Quality control plans may be too rigid and inflexible, preventing the adaptation and improvement of processes.
• Quality control plans may be complex and difficult to understand for those responsible for implementing them, leading to confusion and errors.

Other approaches related to Quality control plan

A Quality control plan is a document that details the product, service or process characteristics that should be monitored in order to achieve expected results. There are several other approaches related to quality control plans that can help to improve the stability and predictability of results. These include:

• Statistical Process Control (SPC): SPC is a method of tracking and analyzing data to identify trends and patterns that can be used to improve product quality. It can be used to detect changes in process performance and identify potential causes of defects.
• Root Cause Analysis (RCA): RCA is used to identify the root causes of quality issues. It involves analyzing data, interviewing stakeholders, and using problem-solving techniques to identify potential causes of quality issues.
• Total Quality Management (TQM): TQM is an approach that focuses on continuous improvement of processes, people, and products. It involves identifying processes that need improvement, setting quality goals, and implementing quality initiatives to achieve those goals.

In summary, a Quality Control Plan is a document that identifies and monitors product, service or process characteristics in order to achieve expected results. Other approaches related to quality control plans include Statistical Process Control (SPC), Root Cause Analysis (RCA), and Total Quality Management (TQM). These approaches can help to improve the stability and predictability of results.

Quality control plan — recommended articles

Quality control — Quality assurance — DMAIC methodology — Internal benchmarking — Non-conformity — ISO 9001 — Controlling — Managerial controlling — Feature-driven development

References

• Evans, J. R., & Lindsay, W. M. (1999). The management and control of quality.
• Kackar, R. N. (1989). Off-line quality control, parameter design, and the Taguchi method. In Quality Control, Robust Design, and the Taguchi Method (p. 51-76). Springer US.
• Knappenberger, H. A., & Grandage, A. H. E. (1969). Minimum cost quality control tests. AIIE Transactions, 1(1), 24-32.
• Control plan on ASQ

Author: Slawomir Wawak