Introduction to histograms and Line of Balance graphs

A histogram or a Line of Balance graph is displayed against a project in Project Viewer if one has been included in the view that you currently have open. They appear by default at the bottom of the bar chart.

Histograms

Histograms display graphical views of resource usage. Histograms are useful resource management tools because they allow you to anticipate any fluctuations in resource usage and take corrective action, hence avoiding periods of over- or under-allocation.

A histogram uses a histogram report, which can contain one or more resource graph definitions. For example, a histogram could be configured to compare a resource's allocation and availability, or to monitor the cost of a resource.

As well as containing more than one resource graph definition, a histogram can also graph more than one resource at the same time within the same graph.

Line of Balance graphs

Line of Balance graphs are used to analyse and plan work or production rates in groups of tasks in which repeated work items are drawn with a series of linked steps to plan a single deliverable - these are known as 'unit networks'. One use of unit networks would be for planning the construction of a number of house plots, in which the same tasks are carried out for each plot, with each unit network comprising the activities that must be carried out during the construction of a particular plot.

Each activity within a unit network represents a different 'stage' that must be carried out by a particular gang or trade. In a Line of Balance graph, the repetitive work of each stage is shown as a single line. The rate of production of a stage is indicated by the steepness of its line - the steeper the line, the greater the rate of production - and the relationship of one stage to the subsequent stage is indicated by the space between the lines.