Design Pattern: RM(14) Linear charts


A set of incoming alarms has been registered. Tknow the temporal evolution of alarms.


The human operator needs to visualize how the alarm activations change over time.


Use line charts to display the quantitative value of alarm activations over a continuous interval. In most cases, this interval is a time span, and the line chart describes how the object's variable changes over this time interval. Besides the individual values themselves the most significant information that can be derived from it is the gradient of the curve, which provides information about the intensity of the attribute's change over time. Also, minimum and maximum values can be easily identified from such a representation.

Known uses
Fig1. Embedded line chart in the DeltaV process control system
Fig2.Linear chart provided by the SIMATIC PCS 7 Process Control system

The expressive power of this type of chart lies in the user's ability to interpret the development of a magnitude over an interval, such as time, by merely looking at the way the graph line moves from left to right. (Ware, C. (2012). Information visualization: Perception for design Elsevier.)