8.3 Control Quality – A Guide to the Project Management Body of Knowledge (PMBOK® Guide), Fifth Edition

8.3 Control Quality

Control Quality is the process of monitoring and recording results of executing the quality activities to assess performance and recommend necessary changes. The key benefits of this process include: (1) identifying the causes of poor process or product quality and recommending and/or taking action to eliminate them; and (2) validating that project deliverables and work meet the requirements specified by key stakeholders necessary for final acceptance. The inputs, tools and techniques, and outputs of this process are depicted in Figure 8-11. Figure 8-12 depicts the data flow diagram of the process.

The Control Quality process uses a set of operational techniques and tasks to verify that the delivered output will meet the requirements. Quality assurance should be used during the project's planning and executing phases to provide confidence that the stakeholder's requirements will be met and quality control should be used during the project executing and closing phases to formally demonstrate, with reliable data, that the sponsor and/or customer's acceptance criteria have been met.

The project management team may have a working knowledge of statistical control processes to evaluate data contained in the control quality outputs. Among other subjects, the team may find it useful to know the differences between the following pairs of terms:

  • Prevention (keeping errors out of the process) and inspection (keeping errors out of the hands of the customer).
  • Attribute sampling (the result either conforms or does not conform) and variables sampling (the result is rated on a continuous scale that measures the degree of conformity).
  • Tolerances (specified range of acceptable results) and control limits (that identify the boundaries of common variation in a statistically stable process or process performance).

8.3.1. Control Quality: Inputs

8.3.1.1 Project Management Plan

Described in Section 8.1.3.1. The project management plan contains the quality management plan, which is used to control quality. The quality management plan describes how quality control will be performed within the project.

8.3.1.2 Quality Metrics

Described in Section 4.2.3.1. A quality metric describes a project or product attribute and how it will be measured. Some examples of quality metrics include: function points, mean time between failure (MTBF), and mean time to repair (MTTR).

8.3.1.3 Quality Checklists

Described in Section 8.1.3.4. Quality checklists are structured lists that help to verify that the work of the project and its deliverables fulfill a set of requirements.

8.3.1.4 Work Performance Data

Described in Section 4.3.3.2. Work performance data can include:

  • Planned vs. actual technical performance,
  • Planned vs. actual schedule performance, and
  • Planned vs. actual cost performance.

8.3.1.5 Approved Change Requests

As part of the Perform Integrated Change Control process, a change log update indicates that some changes are approved and some are not. Approved change requests may include modifications such as defect repairs, revised work methods, and revised schedule. The timely implementation of approved changes needs to be verified.

8.3.1.6 Deliverables

Described in Section 4.3.3.1. A deliverable is any unique and verifiable product, result, or capability that results in a validated deliverable required by the project.

8.3.1.7 Project Documents

Project documents may include, but are not limited to:

  • Agreements,
  • Quality audit reports and change logs supported with corrective action plans,
  • Training plans and assessments of effectiveness, and
  • Process documentation such as those obtained using either the seven basic quality tools or the quality management and control tools shown in Figures 8-7 and 8-10.

8.3.1.8 Organizational Process Assets

Described in Section 2.1.4. The organizational process assets that influence the Control Quality process include, but are not limited to:

  • The organization's quality standards and policies,
  • Standard work guidelines, and
  • Issue and defect reporting procedures and communication policies.

8.3.2. Control Quality: Tools and Techniques

8.3.2.1 Seven Basic Quality Tools

Described in Section 8.1.2.3. The seven basic quality tools are illustrated conceptually in Figure 8-7.

8.3.2.2 Statistical Sampling

Described in Section 8.1.2.6. Samples are selected and tested as defined in the quality management plan.

8.3.2.3 Inspection

An inspection is the examination of a work product to determine if it conforms to documented standards. The results of an inspection generally include measurements and may be conducted at any level. For example, the results of a single activity can be inspected, or the final product of the project can be inspected. Inspections may be called reviews, peer reviews, audits, or walkthroughs. In some application areas, these terms have narrow and specific meanings. Inspections also are used to validate defect repairs.

8.3.2.4 Approved Change Requests Review

All approved change requests should be reviewed to verify that they were implemented as approved.

8.3.3. Control Quality: Outputs

8.3.3.1 Quality Control Measurements

Quality control measurements are the documented results of control quality activities. They should be captured in the format that was specified through the Plan Quality Management process (Section 8.1).

8.3.3.2 Validated Changes

Any changed or repaired items are inspected and will be either accepted or rejected before notification of the decision is provided. Rejected items may require rework.

8.3.3.3 Verified Deliverables

A goal of the Control Quality process is to determine the correctness of deliverables. The results of performing the Control Quality process are verified deliverables. Verified deliverables are an input to Validate Scope (5.5.1.4) for formalized acceptance.

8.3.3.4 Work Performance Information

Work performance information is the performance data collected from various controlling processes, analyzed in context and integrated based on relationships across areas. Examples include information about the project requirements fulfillment such as causes for rejections, rework required, or the need for process adjustments.

8.3.3.5 Change Requests

If the recommended corrective or preventive actions or a defect repair requires a change to the project management plan, a change request (Section 4.4.3.1) should be initiated in accordance with the defined Perform Integrated Change Control (4.5) process.

8.3.3.6 Project Management Plan Updates

Elements of the project management plan that may be updated include, but are not limited to:

8.3.3.7 Project Documents Updates

Project documents that may be updated include, but are not limited to,

  • Quality standards;
  • Agreements;
  • Quality audit reports and change logs supported with corrective action plans;
  • Training plans and assessments of effectiveness; and
  • Process documentation, such as information obtained using the seven basic quality tools or the quality management and control tools.

8.3.3.8 Organizational Process Assets Updates

Elements of the organizational process assets that may be updated include, but are not limited to:

  • Completed checklists. When checklists are used, the completed checklists become part of the project documents and organizational process assets (Section 4.1.1.5).
  • Lessons learned documentation. The causes of variances, the reasoning behind the corrective action chosen, and other types of lessons learned from control quality are documented so they become part of the historical database for both the project and the performing organization.