Project Time Management Terms

by Project Management Process Group

1. Plan Schedule Management

• Schedule Management Plan. A component of the project or program management plan that describes how to estimate the project work, track the project progress, and report on it.
• Project Schedule Model Development. The methodologies and tools used to develop the schedule, along with the data they contain.
• Accuracy Levels. The rounding used when deriving activity duration estimates for different life cycle phases.
• Units of Measure. The rules for how estimates should be stated, such as staff hours, days, materials tons, and cubic yards.
• Control Thresholds. The level of variance the schedule can experience before taking action, typically expressed as a percentage of time.

2. Define Activities

• Activity. A unique, scheduled task that must be executed to complete work on the project.
• Rolling Wave Planning. A form of progressive elaboration that focuses on planning the imminent project activities in more detail than activities further in the future.
• Activity list. A list of all the activities that must be accomplished to deliver the work packages.
• Activity attributes. A complete description of the activity, such as activity codes, predecessor activities, and successor activities.
• Milestone list. A list of significant points or events in the project.

3. Sequence Activities

• Precedence Diagramming Method (PDM). Also called “activity-on-node” (AON), a graphical representation of activities in the project with nodes to represent them and one or more logical relationships to graphically link them, showing the sequence in which these activities are to be performed.
• Dependency. A relationship between two or more activities where one activity must be started or completed before another related activity may be started or completed.
• Lag. In a finish-to-start relationship between two scheduled activities, the amount of time a dependent activity must wait after its predecessor finishes before it can start.
• Lead. In a finish-to-start relationship between two scheduled activities, the amount of time a dependent activity can be advanced with respect to its predecessor.
• Project schedule network diagrams. A graphical representation of the logical relationships between all the activities to be completed on a project.

4. Estimate Activity Resources

• Resources. People, equipment, locations, or anything else that project manager needs in order to do all of the activities planned.
• Resource Calendars. A calendar that shows the days that a particular resource is available to be used on the project and the days when it will not be used.
• Risk Register. The documented list of all identified risks on the project and their characteristics.
• Alternative Analysis. Figuring out all the possible different ways that a potential outcome may be achieved and then making a decision about which method is best.
• Published Estimating Data. A database of known quantities or costs relating to completion of activities in the project.
• Bottom-up Estimating. The process of breaking down the activity into smaller pieces, then rolling up the estimates upwards to the level of the original activity to arrive at a total cost.
• Activity Resource Requirements. The resources required to complete the activities in the activity list.
• Resource Breakdown Structure. A breakdown of the resources required to complete the project, by category and type.

5. Estimate Activity Durations

• Analogous Estimating. An estimating process that bases estimates upon similar activities with similar resource category and types from a similar type of projects executed earlier.
• Parametric Estimating. An estimating technique that uses statistical techniques to calculate cost or duration values for activities based on data from similar earlier projects.
• Three-point Estimating. A formula that takes into consideration uncertainty factor when it calculates a weighted average of the optimistic, most likely, and pessimistic estimates.
• Reserve Analysis. An analytical technique that takes care of uncertainty by adding extra time—also called buffers or time reserves—to the schedule or extra cost.
• Work Periods. The activity duration estimates, usually expressed in hours or days—smaller projects— or in weeks or months— larger projects.
• Activity Duration Estimates. Quantifiable estimates expressed as the number of work periods needed to complete a schedule activity.

6. Develop Schedule

• Schedule Network Analysis. A group of techniques that develops the project schedule, such as critical path and critical chain method, what-if analysis, and resource leveling.
• Critical Path Method (CPM). A schedule network analysis method that calculates the theoretical early start, early finish, late start, and late finish for each activity on the project schedule. These theoretical numbers tell us how much flexibility we have on the schedule and also the minimum project duration.
• Float—or Slack. The amount of time an activity may be delayed without delaying the project finish date.
• Critical Chain Method. A critical path that accounts for limited or restricted resources, where a project manager places buffers to any schedule path.
• Resource Leveling. A technique to optimize resource assignments that adjusts the start and finish dates of schedule activities based on the availability of resources. Critical path usually gets longer.
• Resource Smoothing. A technique to optimize resources that ensures demand for resources does not exceed certain limits. Critical path is not allowed to change.
• Crashing. A schedule compression technique that adds more resources to the critical path activities, from either inside or outside the organization.
• Fast Tracking. A schedule compression technique that overlaps activities or phases that a project manager would prefer to complete in sequence.
• Schedule Baseline. The developed and approved schedule, result of several iterations. Changeable only through formal change control process.
• Project Schedule. The working timeframe the project will take, living document. Changeable by the project manager with no formal change control.

7. Control Schedule

• Work Performance Data. Data—actual raw information—on what is occurring related to the schedule.
• Work Performance Information. The refined work performance data that shows a comparison of the data with the schedule baseline.
• Schedule Forecasts. Updated projections of future performance based on actual performance.