Quick Link for Quality Management
Quality Management 8.1 Plan quality
Quality Management 8.2 perform quality assurance
Quality control involves monitoring and recording specific project
results to assess performance and recommend necessary changes. Project results
include both product deliverables and project performance measures such as cost
and schedule.
Project teams should know the differences between:
·
Prevention (keeping errors out of the process)
and inspection (keeping errors away from the customer).
·
Attribute sampling (the result conforms or it does
not) and variables sampling (results are measured to determine the degree of
conformity).
·
Tolerances (the result is acceptable if it's
within the range specified by the tolerance) and control limits (the process is
in control if the result falls within the control limits).
Perform quality control
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Inputs
|
Tools
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Outputs
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1. Project
management Plan
2. Quality
metrics
3. Quality
checklists
4. Work
performance measurements
5. Approved
change requests
6. Deliverables
7. Organizational
process assets
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1. Cause
and effect diagrams
2. Control
charts
3. Flowcharting
4. Histogram
5. Pareto
chart
6. Run
chart
7. Scatter
diagram
8. Statistical
sampling
9. Inspection
10. Approved
change requests review
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1. Quality
control measurements
2. Validated
changes
3. Validated
deliverables
4. OPA
updates
5. Change
requests
6. Project
management Plan updates
7. Project
document updates
|
Seven Key lnputs for Perform Quality Control:
1. Project Management Plan: Contains the
quality management plan which documents how quality control is to be handled.
2. Quality Metrics: Also known as
operational definitions, metrics describe how something will be measured.
Quality metrics might include failure rates and reliability. A related project
performance metric might measure whether an activity is on time (A decision
would have to be made as to whether on time means starting on time, finishing
on time, or both).
3. Quality Checklists: A structured tool
to verify that all steps in a process have been performed. Checklists are often
used in the quality management process, especially in a complex or for tasks
performed frequently.
4. Work Performance Measurements: Contains
measures of actual progress which are compared to planned progress. These
metrics include:
·
Planned vs. actual technical performance
·
Planned vs. actual schedule performance
·
Planned vs. actual cost performance
5. Approved Change Requests: Approved
changes may affect work methods, schedules, and defect repairs. The correct and
timely implementation of approved changes must be verified.
6. Deliverables: Described in Section
4.3.3.1 (any verifiable product or result).
7. Organizational Process Assets:
Organizational Process Assets that may affect quality control include:
·
Quality standards and policies
·
Standard work guidelines
·
Procedures and policies for issue reporting,
defect reporting, and communication
1. Ten Key Tools for Perform Quality Control:
1. Cause and Effect Diagram: You must know
that cause and effect diagrams are also called lshikawa or Fishbone diagrams.
They are used to illustrate the possible factors that may be causing or
influencing certain problems. PMI also emphasizes that they may be used to
stimulate thinking and discussion.
2. Control charts: Control charts are used
to determine whether a process is stable (under control) and is therefore
producing predictable results. The charts track three major types of data:
a.
Specification limits are requirements in the
contract,
b.
Control limits define points at which corrective
action is considered and
c. There
is a planned goal (the perfect outcome).
Control charts are graphic, time-based
displays of process results. The charts are used to determine whether a process
is under control. In other words, are the differences in the results caused by
random variations or are they the result of "special causes" that
indicate a need for corrective action? The following list reviews key points:
·
Control limits indicate how much variation is
inherent in a process. control limits are often at a range of plus or minus
three sigma (where sigma is the standard deviation of process outcomes).
·
Outcomes outside the control limits are referred
as special causes (or assignable causes) and indicate a need for corrective
action.
·
Specification limits are established in the
contract and represent customer demands (how much variation is allowable before
the results are rejected or penalized in some way). This concept is also
referred to as a tolerance.
3. Flow charting: Described in Section
8.1.2.7. Flowcharts are diagrams used to help analyze how problems occur. Most
flowcharts show activities, decision points, and the sequence in which process
steps occur. These diagrams help improve processes and help anticipate where
problems might occur.
4. Histogram: A vertical bar chart that
rank orders or prioritizes data. The next tool, Pareto chart, is an example of
a histogram.
5. Pareto chart: A histogram (vertical bar
chart) ordered by the frequency of occurrence that shows results by specific
causes. The greatest cause of defects or variances is shown as the tallest bar
on the left of the chart. The causes are rank ordered from left to right, and
the rank ordering is used to guide corrective action-the greatest cause of
variance is worked on first.
The tool was named after an
Italian economist who discovered that 80% of the wealth in a particular region
in Europe was held by only 2a% of the population. This discovery eventually was
dubbed the 80/20 rule, indicating the importance of focusing efforts toward
improvement on the "significant few."
6. Run chart: Trend analysis is performed
using a run chart, which is a line graph that plots data points in the order in
which they occur (i.e., on a time scale). The data may show:
·
Variation
·
Declines or improvements over time
·
Trends
7. Scatter Diagram: Shows the relationship
between two variables known as the dependent and the independent variables.
8. Statistical Sampling: Choosing part of
a population for inspection. For example, one might examine 150 of the 1,000 welds
on a bridge construction project to determine whether the welds conform to
requirements. Sampling is done to reduce the cost of quality control.
For the exam, you should know the conditions under which sampling is most
appropriate:
·
When the population is large
·
When the cost of inspection is high
·
When destructive testing is required (duh)
·
When you believe there are not many defects
Attribute sampling looks for the
presence or absence of particular defects. Variable sampling provides the basis
for control charts by numerically measuring the degree of conformity for
particular factors.
9. Inspection:
The examination of a work product to determine whether it conforms to
standards. Inspections generally include measurements and may be conducted at
any level (the final product, a sub-system, or a single activity). As before,
other names include reviews, audits, and walkthroughs.
10. Approved
Change Requests Review: These reviews are designed to ensure that approved
change requests were implemented correctly.
Seven Key Outputs for Perform Quality Control:
1. Quality Control Measurements: As
described in quality assurance, these measurements are used as feedback to QA
to reevaluate any quality standards currently in use.
2. Validated Changes: Repaired or changed
items are inspected and either accepted or rejected. Rejected items may require
rework.
3. Validated Deliverable: A major goal of
quality control is to ensure that deliverables are correct. Validated deliverable are inputs to Verify Scope (Section 5.4) for formal acceptance.
4. Organizational Process Assets Updates:
Recording the use of checklists and incorporating those records into the
historical database of the organization.
5. Change requests: If recommended
corrective actions, preventive actions or defect repairs lead to change
requests, the requests must be processed using integrated change control.
6. Project management plan updates:
Portions of the project management plan that may be updated include:
·
Quality management plan
·
Process improvement plan
7. Project document updates: Documents
that may be updated include quality standards.
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