Project Management Terminology

The following definitions describe how these terms are used in ProjectLibre; your organization may use the terms differently, but at least these definitions provide an unambiguous glossary for usage understanding how this software works. A more complete list of definitions1 is available for those who need more definitions.

Account: An account is used in a Cost Breakdown Structure (CBS) to represent a place where cost from tasks or resources can be aggregated.

Allocation: Tasks are allocated to resources during the planning stage of the project. Actual assignments are part of the scheduling process. One important point is that simply making such assignments does not guarantee the needed resource will be available.

Assignment: Resources are assigned to complete tasks according to the best estimate of the planners of the project. Assignment is an important part of the scheduling process.

ACWP: Actual Cost of Work Performed (ACWP) is the aggregation of all costs necessary to complete the work for the project.

BCWP: Budgeted Cost of Work Performed (BCWP) is the aggregation of budgeted costs performed in completing the project.

BCWS: Budgeted Cost of Work Scheduled (BCWS) is the aggregation of budgeted costs predicted for work scheduled to complete the project.

CBS: The Cost Breakdown Structure is made up of resource accounts broken down to fit the elemental tasks spelled out in the Work Breakdown Structure (WBS) for the development. The CBS organizes accounts into a framework that enables costs to be aggregated independent of the WBS or the RBS.

CPI: The Cost Performance Index (CPI) is equal to the BCWP/ACWP. When this index is less than 1, the project is over budget. If the CPI > 1 the costs for the project are under budget. When the index is equal to 1 the costs for the project are on budget. When the index is greater than one, the project is under budget.

Estimate: A prediction of the expected amount of effort or time needed to complete a given task.

Milestone: A milestone is a special task representing an event in your project; it is a task with an effort of 0.00h. It is typically used to mark a major outcome; for example, the completion of a deliverable satisfactory to and accepted by the customer.

PERT: The Program Evaluation and Review Technique (PERT) is an enhancement to the Critical Path Method (CPM). Task effort estimates in CPM are point estimates, while task effort estimates in PERT are computed by weighting the Optimistic, Most Likely, and Pessimistic estimates [(O + 4*M + P)/6].

PERT Distribution: This distribution is a simplified way to calculate an Expected estimate from the Optimistic-, Most Likely-, and Pessimistic estimates.

Resource: A resource can be one of three types: Work, Material, or Team. All resources must belong to a Research Group.

Resource Group: A resource group is a collection of similar resources.

Resource Team: A resource team consists of a number of resources working together for a common purpose.

RBS: The Resource Breakdown Structure (RBS) organizes resources into hierarchical groups and structure.

SPI: The Schedule Performance Index (SPI) is equal to the BCWP/BCWS. When this index is less than 1, the project is over budget. If the CPI > 1 the costs for the project are under budget.

Summary Task: A summary task has subordinate tasks (sub tasks) and rolls up information based on these sub tasks.

Task: A task is a unit of work; resources are usually allocated at the task level.

WBS: Work Breakdown Structure (WBS) is used to decompose large projects down into manageable chunks to ease planning and management.

Tasks, Resources, and Costs

Three of the most important terms in the list above are tasks, resources, and costs; they are the core elements to be manipulated and organized in project management. We will elaborate in later sections on each of these concepts and how to work with them in ProjectLibre but for this introductory section the following paragraphs are meant to fix these concepts firmly in the user’s mind.

Tasks are the fundamental building blocks for a project schedule. The definition in the previous section was very terse, but meaningful – each task represents a unit of work, a step toward completing a project. As is likely obvious, tasks often need to take a hierarchical form to help in decomposing a complex project down into manageable and understandable chunks. That is exactly what the definition of a WBS states; therefore, the WBS is made up of a hierarchical tree of decomposed tasks. The organizational structure depicted by the WBS is meant to make it easier to understand how the various elements of a complex task fit together and ProjectLibre is a great tool for depicting that structure of tasks and how they interact.

Resources are shared entities; all the people and materials owned by your organization are shared by all projects supported by the organization. People resources have the type “Work” (expressed in hours or days – time) and materials have the type “Material” (expressed in a quantity – bags of cement, for example). ProjectLibre has a spreadsheet depiction for managing resources (figure 1). These typical spreadsheet headings can be tailored to suit the needs of specific projects.

Figure 1. Resource spreadsheet

“Cost”1 refers to the monetary value or financial pricing of a specific project activity and is the most commonly used way of aggregating resources in a project to be managed. As figure 1 suggests, it is typical to assign hourly (or weekly or monthly) rates to people resources. Similarly, the amount of money paid to acquire materials, expressed as a dollar cost, gives an indication of the relative value of different materials.