Performing Quality Control


The third element of Project Quality Management is Perform Quality Control. The PMBOK 3rd ed. describes Perform Quality Control as "monitoring specific project results to determine if they comply with relevant quality standards and identifying ways of eliminating causes of unsatisfactory results."

Q.

Quality Control is performed:

 

A.

At the start of a project

 

B.

When defects are identified

 

C.

For the life of the project

 

D.

After the project is accepted


The answer is C: for the life of the project. The PMBOK goes on to list seven inputs, ten tools and techniques, and ten outputs involved in Quality Control.

Q.

The seven inputs to Quality Control are the Metrics, the Quality Management Plan, Checklists, Work Performance Information, Approved Change Requests, Organizational Assets, and:

 

A.

Deliverables

 

B.

Ishikawa Diagrams

 

C.

Flowcharts

 

D.

Quality audits


The answer is A, deliverables, which, after all, are the very purpose of undertaking the project from the outset.

Specifically, the PMBOK says the ten tools and techniques used in Quality Control are Cause and Effect Diagrams, Histograms, Run Charts, Scatter Diagrams, Control Charts, Pareto Diagrams, Statistical Sampling, Flowcharting, Defect Repair Review, and Inspection. We already have seen that quality cannot be "inspected into" a product or process; however, that does not imply that we should not use inspection.

Q.

What should be the role of inspection in Quality Control?

 

A.

To determine the level of performance against standards

 

B.

To prove that you are producing a quality product

 

C.

To satisfy upper management and the customer

 

D.

Minimally useful because quality cannot be inspected in


The answer is A, to determine the level of performance against standards. Although one could argue that elements of B and C have some value, A is the best answer. We inspect to see where we are in terms of quality. Inspection can take many forms, including visual examination, precise measurements with instruments, tasting, and testing. In some instances, the testing can include destructive testing, which renders the tested item useless. An example of this might be the collision testing of prototype automobiles to determine their resistance to damage or ability to protect occupants.

Q.

Another term for Cause and Effect Diagrams is:

 

A.

Trend Analysis

 

B.

Ishikawa Diagrams

 

C.

Scatter Diagrams

 

D.

Metrics


The answer is B, Ishikawa Diagrams, or as they are sometimes called, Fishbone Diagrams because of their physical structure. Figure 12-1 is an example of a Cause and Effect Diagram.

Figure 12-1. Cause and Effect Diagram.


Yet another type of charting is known as Scatter Diagrams, which are used to track one variable against another. Examples are tracking operation speed of equipment vs. breakdowns or age of automobile drivers vs. number of accidents. The PMBOK lists a tool known as Trend Analysis to analyze such charts. This tool predicts, mostly through extrapolation, what the future results will be, given the historical data.

Control Charts are a category under a statistical technique known as Statistical Process Control or SPC. Control Charts are useful in Quality Control in that they offer a graphical picture of data over a specific time period for a process. This usually is plotted with time on the horizontal axis and the data values at specific times on the vertical axis. The diagram in Figure 12-2 is an example of a Control Chart that plots data around a mean value. Note that there are zones on either side of the expected average or mean value that are labeled LCL and UCL, which stand for Lower Control Limit and Upper Control Limit. Data that falls within the LCL and UCL is considered normal variation in the process, whereas data outside those limits is considered abnormal and worth investigating to determine what caused the variation. Note also that data plotted outside the control limits of the chart are labeled as out of control.

Figure 12-2. Plotting data around a mean value.


Defect Repair, or as it is sometimes called, Rework, involves bringing the rejected items to a level that makes them acceptable, and it is frequently an expensive but necessary action. Defect Repair is, therefore, something that should be continually examined to determine the causes for the failures so they may be avoided in the future. From a project management viewpoint, every instance of Rework should be included in the "lessons learned" artifacts of the project to assist those who engage in similar future projects.

Another useful charting technique uses histograms, often called Pareto Diagrams. These diagrams were named for Vilfredo Pareto (18481923), an Italian economist who advanced several economic theories on society among which were that 80% of the wealth is controlled by 20% of society. This was by no means intended to be a precise measure, but his mathematical formula for this theory gave rise to the heuristic known as the 80/20 Rule. This rule says that 80% of problems are the result of 20% of assignable causes. These bar charts are useful in that they allow you to group errors, defects, and other problems into logical groups so that you can focus on solving the most frequent problems first. You should not expect that every time you use a Pareto Diagram, you will come up with an 80/20 breakdown, but that in no way diminishes their value as a Quality Control tool.

Q.

Recording of the causes for Rework could best be done by:

 

A.

Pareto Charts

 

B.

Changes to the project schedule

 

C.

Project Status Reports

 

D.

The Comptroller


The answer is A, Pareto Charts, which allow you to look at not only the causes of failure but also their frequency so that you can target the ones that offer the most improvement if corrected.

Flowcharting allows you to get a picture of processes so that they can be analyzed for possible areas of errors or disconnects that can cause quality problems.

Checklists are used to prove that all steps detailed in the Quality Assurance outputs were completed. Completed Checklists should be included in the historical record of the project and can be useful artifacts in the event of a project audit.

Q.

Quality Checklists are used to:

 

A.

Ensure that Quality Assurance steps were followed

 

B.

Keep quality inspectors busy

 

C.

Inform upper management where failures occur

 

D.

Prevent project audits


The answer is A, Ensure that Quality Assurance steps were followed.

According to the PMBOK, the outputs from Quality Control are QC Measurements; Validated Defect Repair; Updates of the Quality Baseline, the Organization Process Assets and the Project Management Plan; Recommended Corrective and Preventive Actions and Defect Repair; Requested Changes; and Validated Deliverables.

QC Measurements are outputs in the sense that they are fed back to Quality Assurance for use in the revision and refinement of standards, processes, and procedures in the organization. Upon completion of repair of defective items, the items are inspected using the same standard as before, so either the repair action is validated or the item is again rejected and either repair is attempted again or the item is scrapped. QC measurements provide feedback for the updating of the Quality Baseline, the Organization Process Assets, and ultimately the Project Management Plan. Similarly, measurements taken in performing the QC function lead to recommendations for corrective and preventive actions, in addition to recommendations for the repair of defects. Most importantly, QC measurements are used to validate deliverables for the project and assure they are correct and fit for the use intended.

Q.

QC measurements play an important role in improving project quality if they are:

 

A.

Kept in a safe location in the QC organization

 

B.

Part of a feedback system to improve quality

 

C.

Reported to the customer only in the event of a dispute

 

D.

Recorded in the project archives as lessons learned


The answer is B because the measurements, when fed back properly, are key in instituting continuous quality improvement.

As we have seen, quality is an important facet of project management and plays directly with the other eight processes that contribute to managing projects of various sizes and complexity. Although all of the nine processes discussed in the PMBOK have their place in projects, quality is one that is intimately involved in every project, no matter the subject, size, or complexity.



Passing the PMP Exam. How to Take It and Pass It
Passing the PMP Exam: How to Take It and Pass It: How to Take It and Pass It
ISBN: 0131860070
EAN: 2147483647
Year: 2003
Pages: 167
Authors: Rudd McGary

flylib.com © 2008-2017.
If you may any questions please contact us: flylib@qtcs.net