Introduction to resource and cost breakdown structures

You can view projects as resource breakdown structures (RBS) where allocations are grouped under resources, or as cost breakdown structures (CBS), where allocations are grouped under cost centres. The more detail you build into your resource and cost centre hierarchies, the more detail you can display in RBS and CBS views. For example, if you have a 'Plumbers' permanent resource, you can display an RBS view that shows all of the tasks to which the Plumbers resource has been assigned; if you have a 'Plumbers' permanent resource folder, containing resources to represent the individual plumbers that you use, you can display an RBS view that shows all of the tasks to which each individual plumber has been assigned.

To display an RBS view showing all allocations of a specific resource, or to display a CBS view showing all allocations of a specific cost centre:

Double-click a resource or cost centre in the project view.
Right-click a resource or cost centre in the project view and select Open RBS or Open CBS.
Right-click an allocation of the resource or cost centre in the bar chart and select Open RBS or Open CBS from the menu that appears.

The RBS or CBS view initially appears as illustrated below, with a summary task representing the resource or cost centre and individual resource or cost allocations, identified by the name of the task to which the allocation is assigned, below the summary task:

An RBS view

When a RBS view is displayed, a RBS button appears in the status bar; when a CBS view is displayed, a CBS button appears in the status bar.

You can specify whether summary tasks are displayed for each resource or cost centre in RBS and CBS views.

Initially, each individual allocation appears on its own line in RBS and CBS views. You can contract the allocations in RBS and CBS views so that a resource or cost centre's allocations appear on the same line as far as possible.

To display an RBS or CBS view of all of the resources or cost centres within a resource or cost centre folder, right-click the folder in the project view and select Open RBS or Open CBS (you cannot display RBS or CBS views for folders by double-clicking them or by right-clicking allocations in the bar chart). An RBS or CBS view of all of the resources within the selected folder is displayed underneath a main summary task that represents the folder itself. This is illustrated below, where a RBS view is displayed for the Site Resources folder, which contains two individual resources: Bricklayers and Carpenters:

RBS view of the Site Resources folder, which contains two individual resources

In RBS or CBS views such as these, you can expand and collapse the RBS or CBS view for each subordinate resource or cost centre individually.

To display a RBS or CBS view of more than one individual resource or cost centre, CTRL-click the resources or cost centres in the project view, then right-click one of them and select Open RBS or Open CBS.

Initially, RBS and CBS views include the entire programme of projects in their scope; to restrict a RBS or CBS view to one or more branches of the hierarchy, display the RBS or CBS view then hold down CTRL and click the relevant branch, or branches, in the project hierarchy that is displayed in the project view.

If a task has allocations of more than one resource or more than one cost centre, it is listed in the RBS or CBS view below each resource or cost centre that is allocated to it. If a task has no resource or cost centre allocations, it is not displayed in the RBS or CBS view.

You can edit allocations in RBS or CBS views, and you can edit the properties of a resource or cost centre by right-clicking the summary task that represents the resource or cost centre in the RBS or CBS view and selecting Properties. Editing a resource or cost centre's properties does not affect any of its existing allocations, but the revised settings are applied to any future allocations of the resource or cost centre.

You can move and size cost allocations in CBS views, and you may be able to move and size resource allocations in RBS views, depending on their resource modelling settings and what other allocations (if any) are on the same task. For example, you cannot change the size of a fixed or non-modelled resource allocation.

You can attach annotations to allocation bars in RBS and CBS views, but you cannot attach annotations to the summarising tasks, or to the chart background.

To close an RBS or CBS view:

Click a chart or summary group in the project view. If you close an RBS or CBS view in this way, the view is updated to display the chart or summary group that you have clicked.
Right-click an allocation in the RBS or CBS view and select Close RBS or Close CBS from the menu that appears. If you close an RBS or CBS view in this way, you return to a bar chart view of the chart or summary group in which the allocation that you right-clicked is located.
Click or in the status bar. If you close an RBS or CBS view in this way, you return to the programme chart.