activity

an element of work performed during the course of a project. An activity normally has an expected duration, an expected cost, and expected resource requirements. Activities are often subdivided into tasks.

activity delay

the maximum amount of time that an activity can be delayed due to lack of resources.

activity-on-arrow (AOA)

see arrow diagramming method.

activity-on-node (AON)

see precedence diagramming method.

activity priority

a priority value that is assigned to activities to provide an ordering for activities that are waiting for resources (during resource-constrained scheduling).

activity splitting

The act of dividing activities into segments during resource allocation. In some cases, preemption of activity segments can free a resource to be used by a more critical activity.

actual cost of work performed (ACWP)

total costs incurred (direct and indirect) in accomplishing work during a given time period. See also earned value.

actual finish date (AF)

the calendar date when work on an activity actually ended. The AF date must be prior to the timenow date.

actual start date (AS)

the calendar date when work on an activity actually began. The AS date must be prior to the timenow date.

aggregation

the use of activity resource requirements to calculate total resource needs rather than to constrain the project schedule. Normally, resource requirements are used to perform resource-constrained scheduling.

alignment type

an identification of the type of constraint that is associated with a target date. The following types are available:

• finish on

• finish on or after

• finish on or before

• start on

• start on or after

• start on or before

• mandatory start

• mandatory finish

arrow

the graphic representation of an activity. See also arrow diagramming method.

arrow diagramming method

a network diagramming technique in which activities are represented by arrows. The tail of the arrow represents the start of the activity, and the head represents the finish of the activity (the length of the arrow does not represent the expected duration of the activity). Activities are connected at points called nodes (usually drawn as small circles) to illustrate the sequence in which the activities are expected to be performed. See also precedence diagramming method.

as-of date

see timenow date.