Understanding Metrics
A metric is a standard or measure for use in determining how well a project is planned and executed.
What is a Metric?
Metrics contain formulas, weightings and tripwires (thresholds). Formulas are used to calculate results as part of an analysis. Tripwire thresholds are used to flag and filter activities that exceed given levels.
Metric results can be numeric (for example, cost or duration) or percentages (for example, percentage of total project duration). Percentages are useful for portraying results within a given context. Acumen uses metric libraries to group metrics for project analysis. Standard metric libraries pertaining to schedule quality, cost, project performance, risk exposure, Earned Value, the DCMA 14 Point Assessment, and more are included within the tool. For example, metrics can be organized by categories, project attributes, or along a project lifecycle. Organizing the metrics differently allows you to customize your project or program analysis.
To What Do Metrics Apply?
All project data is stored in a tabular manner with each activity represented as a row of data. For that activity, each activity attribute is listed in a different column. The data is then aggregated either across the spreadsheet or down the spreadsheet.
Acumen metrics are:
- Calculated across a ribbon.
- Calculated down a phase.
- Calculated for the intersection of a phase/ribbon.
Types of Fields
When you create metric formulas, you can reference four types of fields:
- Activity fields are the most commonly used type of field in an Acumen metric formula. All fields that are defined in the field mapping during a project import are exposed as activity fields in the metric editor. These include user defined and code fields.
- Some Project fields fields get automatically imported during a project import. These fields are automatically exposed and can be used within metric formulas. When a metric is calculated that contains a project field reference, the specific project field value for the activity in question is used. A single metric calculation may contain activities from multiple projects. In this instance, the appropriate project level field value will be used for each activity (for example, "time now" may be different for each of the projects).
- Workbook fields are summated values that are calculated at the workbook level (that take into account all activities within the workbook).
- Dynamic fields have different values depending on the context in which they are being used. "Period Start" and "Period End" are both dynamic fields. When Period Start and Period Finish are being applied to a phase analysis, Period Start and Period Finish relate to the start and finish of the phase in question. When being used within the context of a ribbon, Period Start and Period End relate to the start and end date of the ribbon.
In the context of ribbons, the earliest start of the first activity in the ribbon (time independent) is Period Start. Similarly, the end of the last activity in the ribbon is Period Finish.
In the context of a phase, Period Start is the start of a phase and Period End is the end of the phase.
Metric formulas are generally written within the context of an activity. However, if you reference fields outside of the activity context (for example, project and/or workbook), you are able to model how activities relate to, and potentially impact, other contexts.