forProject Encyclopedia

Activity

An Activity, also called a Task, is a measurable, discrete unit of work with a clear start and end. It's the basic building block of a project schedule, and activities are sequenced and linked together to build the overall schedule.

Backward Pass

The Backward Pass is the schedule calculation that works back from the project finish date, following the links between tasks in reverse, to determine the latest each task can start and finish without delaying the project.

Baseline Schedule

A Baseline Schedule is the approved version of a project schedule that serves as the standard against which ongoing schedule performance is measured.

Constraint

In scheduling, a Constraint is an imposed or mandatory date placed on a specific task or milestone.

Contract Milestone

A Contract Milestone is an event specifically named in a contract that represents a schedule commitment to complete a work task by a certain date.

Critical Path

The Critical Path is the sequence of linked tasks that determines the project's finish date. Delay any task on it and the project finishes later. See also the Driving Path.

Critical Path Analysis

Critical Path Analysis is the practice of identifying the Critical and Driving Paths in a schedule, confirming they are credible, and using them to judge where delay will do the most damage.

Critical Path Method (CPM)

Critical Path Method (CPM) is the scheduling calculation that turns task durations and their logical relationships into dates — determining when each task can start and finish, how much float each one has, and which sequence of tasks sets the project's finish date.

Current Schedule

The Current Schedule is the most up-to-date version of a project's schedule, reflecting the latest plans, logic changes, and status updates.

Driving Path

The Driving Path is the sequence of linked tasks that determines the completion date of a specific milestone or task, calculated the same way as the Critical Path but traced back from that milestone rather than from the project finish.

Duration

Duration is the estimated time — in working days or portions of a day — needed to complete a task, based on a specific working calendar.

Duration Percent Complete

Duration Percent Complete is the percentage of a task's planned Duration that has passed as of the status date, calculated as working days completed divided by total working days in the Duration.

Early Finish Date (EF)

The Early Finish Date is the earliest a task can finish: its Early Start Date advanced by the task's Duration across its working calendar.

Early Start Date (ES)

The Early Start Date is the earliest a task can begin, given its predecessor relationships — including their type and any lead or lag — and its working calendar.

Float

Float (also called Slack) is the amount of time a task can be delayed before it affects other tasks or the project's finish date.

Forecast Schedule

The Forecast Schedule is the working set of schedule values for every task — actual start, actual finish, and progress for work already performed, plus forecast dates and durations for work still remaining — updated each status cycle.

Forward Pass

The Forward Pass is the schedule calculation that works forward from the project start date, following the links between tasks, to determine the earliest each task can start and finish.

Free Float

Free Float (also called Free Slack) is the amount of time a task can be delayed without delaying the early start of its immediately following (successor) tasks.

Lag

A Lag is a delay built into a logical relationship, holding the successor task back for a set amount of time after the predecessor condition is met.

Late Finish Date (LF)

The Late Finish Date is the latest a task can finish without delaying the project, given its successor relationships — including their type and any lead or lag — and its working calendar.

Late Start Date (LS)

The Late Start Date is the latest a task can start without delaying the project: its Late Finish Date less the task's Duration across its working calendar.

Lead

A Lead is a planned overlap built into a logical relationship, allowing the successor task to start before the predecessor condition is fully met.

Milestone

A Milestone is a schedule event marking a significant accomplishment, deliverable, or the start or end of a project phase, rather than a task with duration.

Near Critical Path

A Near Critical Path is the second-longest (or third, fourth, and so on) sequence of linked tasks running to the project finish. It isn't driving the finish date today, but it's the likeliest candidate to become the Critical Path if conditions change.

Negative Float

Negative Float (also called Negative Slack) occurs when Total Float in a schedule is a negative number, meaning there isn't enough time to finish a task within its imposed constraints.

Network Schedule

A Network Schedule is a schedule format that shows tasks and milestones along with their logical dependencies (predecessors and successors).

Project Milestone

A Project Milestone is a project-level milestone marking a significant event, a major deliverable, or the start or end of a major project phase.

Relationship

A Relationship is the logical link between two schedule tasks that establishes the order in which they must occur, such as Finish-to-Start, Start-to-Start, Finish-to-Finish, or Start-to-Finish.

Resource

A Resource is any personnel, material, equipment, service, or other cost needed to complete project work.

Schedule Risk Assessment (SRA)

A Schedule Risk Assessment (SRA) is a process that uses statistical or probabilistic techniques to identify and quantify technical, programmatic, and schedule risks affecting a program's schedule.

Simulation

Simulation is a technique that uses random numbers and probability -- most commonly Monte Carlo simulation -- to test how uncertainty affects a schedule's reliability.

Task

A Task, also called an Activity, is an element of work performed during a project, with its own expected duration, cost, and resource requirements.

Total Float

Total Float (also called Total Slack) is the amount of time a task can be delayed from its early start without delaying the project finish date or any fixed constraint date.