While there are many dozens of terms used in Project Management (PM) there are a few terms and concepts that are “must-knows.” These terms form the foundation of PM methodology and mentality.
Constraints: Restrictions set on the start or finish date of a task. You can specify that a task must start on or finish no later than a particular date. Constraints can be flexible (not tied to a specific date) or inflexible (tied to a specific date)
Crashing: Shifting resources to reduce slack time so the critical path is as short as possible. Crashing always raises project costs and is typically disruptive – a project should be crashed with caution. The goal of crashing a project is to reduce the duration as much as possible regardless of cost. It is the opposite of relaxing a project.
Critical Path: The longest time path through the task network. The series of tasks (or even a single task) that dictates the calculated finish date of the project (That is, when the last task in the critical path is completed, the project is completed) The "longest" path (in terms of time) to the completion of a project. If shortened, it would shorten the time it takes to complete the project. Activities off the critical path would not affect completion time even if they were done more quickly.
Critical Path Method (CPM): A Project Management technique invented by American industry in 1958 as a means of controlling costs and schedules. CPM is based on identifying and managing a path of critical activities that determine the project duration. CPM theory is based on the concept that preceding tasks, not probability, determine the course of a project. CPM is frequently used with PERT.
Dependencies: Links between project tasks. There are 3 types of dependencies:
Dummy activity: An imaginary activity with no duration, used to show either an indirect relationship between 2 tasks or to clarify the identities of the tasks.
Duration: The time it takes for an activity to be completed, given the planned amount of material, labor and equipment.
Effort: The amount (not duration) of work required to complete a task. Duration may decrease by adding resources but the effort required will remain the same.
Gantt chart: A bar chart. While visually appealing on a task/duration basis, it is limited because it does not show task or resource relationships well. Its key strength is that it is easy to maintain and read.
Sample Gantt chart
Milestone: A significant task which represents a key accomplishment within the project. Typically requires special attention and control.
Network Diagram: A wire diagram, also known as a PERT network diagram. A diagram that shows tasks and their relationships; it is limited because it shows only task relationships. Its key strength is easy-to-read task relationships.
Sample Network Diagram
PERT: (Program Evaluation and Review Technique) A Project Management technique invented by (for) the U.S. Navy in 1958 as a means of projecting task and project completion and organizing complex sequences of tasks. PERT is based on the probability of an event occurring at a specified time. When used with CPM, it is the most commonly used Project Management methodology.
Project Management: A management philosophy that says that efficient management will yield effective results. Specifically, efficient management of resources and constraints to perform tasks in order to achieve a desired result.
Relaxation: The method that is the opposite of crashing a project. Relaxation is used to lower costs while extending the duration of the project. A typical use of this method is when a project may be relaxed if its resources are need on higher priority projects. This method involves deliberately lengthening the duration of the project with the specific aim of lowering costs as much as possible.
Resources: Time, money, people, equipment and other supplies are generally accepted as resources for planning and executing a project.
Scope: A specific definition of what the project does and does not entail. A well researched and coordinated scope of work is critical to managing expectations of customers and workers alike.
Slack Time: The amount of time a task can be delayed before the project finish date is delayed. Total slack can be positive or negative. If total slack is a positive it indicates the amount of time that the task can be delayed without delaying the project finish date. If negative, it indicates the amount of time that must be saved so that the project finish date is not delayed. (Slack time is also known as float time)
Work Breakdown Structure (WBS) is a detailed, hierarchical (from general to specific) tree structure of deliverables and tasks that need to be performed to complete a project.
Sample WBS
Along with
these terms, there are several key assumptions in PM (PERT/CPM). It is important to understand these
assumptions when researching and designing a project:
Resources Used in This Unit
Goldratt, Eli, Dr., The Goal: A Process of Ongoing Improvement, Great
MS Project, by Microsoft Corporation.
PM Body of Knowledge (PMBOK),
Project Management Institute (PMI)
<Project Management Institute Website>.
Verma, Vijay K., Managing the
Project Team: The Human Aspects of Project Management,
Wiest, Jerome D., and Levy,
Ferdinand K., A Management Guide to PERT/CPM,
© 1996 A.J.Filipovitch
Revised 11 March 2005