Resources in Microsoft Project

In Microsoft Project, a resource is something used to complete project work: commonly a person, but also equipment or a material such as cement or a web server. A resource can be part of the project plan before it is assigned to a task.

Resource types

Project distinguishes resources by how they contribute to a plan:

Type	Represents	How Project uses it
Work	A person, team, or equipment	Work capacity and time available for assignments
Material	A consumable item	Quantity or consumption rate on an assignment
Cost	An expense such as airfare or lodging	A cost attached to an assignment, without work capacity

Material resources can have a material label such as tons, boxes, or yards. Cost resources do not use units because they do not represent an amount of work performed.¹

Shared, local, and generic resources

An enterprise resource belongs to the organization-wide resource list and can be shared across projects. A non-enterprise (local) resource belongs only to the current project. A generic resource describes a staffing requirement or team profile—for example, a carpenter or developer—before a specific person is selected. Enterprise attributes such as rates or availability may require administrator control.

Capacity and assignment units

For work resources, maximum units describe the total capacity available to the project. A value below 100% models part-time availability; a value above 100% can represent several people grouped under one resource. For example, 300% can represent three full-time engineers.

Assignment units describe how much of that available capacity is dedicated to one task. Project normally defaults a work-resource assignment to 100% units, or to the resource’s Max. Units when that value is below 100%. For example, 50% represents half-time effort, while a resource whose Max. Units is 50% defaults to that available capacity. Material assignment units instead represent the quantity or rate of material consumption. Both maximum and assignment percentages are interpreted against the resource’s calendar, so changing the calendar can change the hours represented by the same percentage.¹

Resource schedules and availability

A resource can have a schedule different from the organization’s general hours: different workdays, shift hours, or nonworking days. In desktop Project, the resource’s base calendar and work-week details are edited through Project > Change Working Time. Vacation can be entered as a one-time or recurring nonworking exception. When an absence overlaps the resource’s scheduled work, Project can move or extend assigned work; the effect depends on the task and other available working time.

Calendar-based scheduling is not the only way to express limited capacity. Project can set a resource’s availability percentage for a defined date range without changing the calendar’s working times. The percentage specifies what share of the resource’s time is available to this project during that period; the calendar’s working and nonworking times remain a separate scheduling input. This is useful when someone splits time between projects for a known period.²

Assign resources to tasks

After tasks are in the schedule, desktop Microsoft Project lets you assign resources from the Resource Names column or through Resource > Assign Resources. Assignment units can make an assignment part-time, and a task can have multiple assigned resources. If many resources must be assigned, the Task Information dialog’s Resources tab avoids the 256-character limit of the Resource Names column.

Project Plan 365 uses separate assignment paths: Team > Assign, the Resource Names column, or Task Information > Resources. See its Assign Resource guidance for those product-specific steps.

Adding or changing an assignment can change task duration or other schedule results. When that happens, review the task’s effort-driven setting and the relevant task, calendar, and resource inputs; the change is a scheduling consequence, not necessarily an error.