Specify measures to address measurement objectives.
Measurement objectives are refined into precise, quantifiable measures.
Measurement of project and organizational work can typically be traced to one or more measurement information categories. These categories include the following: schedule and
progress, effort and cost, size and stability, and quality.
Measures may be either base or derived. Data for base measures are obtained by direct measurement. Data for derived measures come from other data, typically by combining two or
more base measures.
Derived measures typically are expressed as ratios, composite indices, or other aggregate summary measures. They are often more quantitatively reliable and meaningfully interpretable
than the base measures used to generate them.
Base measures enable the creation of many derived measures or indicators from the same standard data sources. In addition, there is a direct relationship between measurement
objectives, measurement categories, base measures, and derived measures. This direct relationship is depicted using some common examples in Table 16.1:
Table 16.1: Example Measurement Relationships
As a part of their measurement and analysis activities, projects may also consider the use of Earned Value Management (EVM) for measures related to cost and schedule [GEIA 748 2002].
EVM is a method for objectively measuring cost and schedule progress and for predicting estimated total costs and target completion dates based on past and current performance trends.
Typical EVM data include the planned cost of accomplishing specific and measurable tasks, the actual cost of completing tasks, and earned value, which is the planned cost of the work
actually completed for each task. Using these or similar base measures, the project can calculate derived measures such as schedule and cost variance and more complex measures. These include schedule and cost performance indices. EVM derived
measures can assist with estimating the cost for completion and additional resources that may be required.
To manage projects, an acquirer uses supplier data (i.e., base measures) and supplier-reported derived measures in addition to measures of acquirer progress and output. Supplier
measures required by the acquirer allow the acquirer to comprehensively address measurement objectives and to comprehensively determine the progress of the project. In some cases, these supplier measures will augment acquirer measures (e.g.,
supplier’s schedule performance index and size estimation accuracy).
In most cases, supplier measures are the primary source of data, especially with regard to the development of the acquired product or service. For instance, measurement and analysis
of the product or product components provided by a supplier through technical performance measures is essential for effective management. Technical performance measures are precisely defined measures based on a product requirement, product
capability, or some combination of requirements and capabilities.
It is important to use measures to track high-risk items to closure and to help determine risk mitigation and corrective actions. These supplier measures must be defined in the supplier agreement, including a supplier’s measurement collection requirements and measurement reports to be provided to the acquirer.
Typical Work Products
1. Specifications of base and derived measures
2. Acceptance criteria for supplier measures
Subpractices
1. Identify candidate measures based on documented measurement objectives.
Measurement objectives are refined into measures. Identified candidate measures are categorized and specified by name and unit of measure.
2. Identify existing measures that already address measurement objectives.
Specifications for measures may already exist, perhaps established for other purposes earlier or elsewhere in the organization.
3. Specify operational definitions for measures.
Operational definitions are stated in precise and unambiguous terms. They address two important criteria:
· Communication: What has been measured, how was it measured, what are the units of measure, and what has
been included or excluded?
· Repeatability: Can the measurement be repeated, given the same definition, to get the same
results?
4. Specify acceptance criteria based on operational definitions for measures that come from suppliers to the acquirer in a way
that enables their intended use.
Measures may be provided by the supplier as detailed measurement data or measurement reports. Measures that come from suppliers must be associated with the acquirer’s acceptance
criteria for supplier measures. Acceptance criteria may be captured in measurement specifications or by checklists.
Acceptance criteria should be defined in a way that enables the intended use of supplier measures, such as potential aggregation and analysis. These criteria must include criteria
associated with the collection and transfer mechanisms and procedures that must be performed by the supplier. Consider all characteristics about supplier measures that may impact their use, such as differences in financial calendars used by
different suppliers.
5. Prioritize, review, and update measures.
Proposed specifications of measures are reviewed for their appropriateness with potential end users and other relevant stakeholders. Priorities are set or changed, and specifications
of measures are updated as necessary.