1. Alert Icons: The simplest visualization is perhaps an alert icon, which can be a geometric shape that is either color-coded or shaded various patterns based on its state. Potentially, the most recognizable alert icon is a green, yellow or red circle, whereby the color represents a more or less desirable condition for the KPI.

When to use: These types of visualizations are best used when they are placed in the context of other supporting information, or when you need a dense cluster of indicators that are clearly labeled. Traditional business scorecard dashboards that are laid out in table like format can benefit from this visualization, whereby other adjacent columns of information can be analyzed depending on the state of the alert icon. These types of icons are also useful in reporting on system state, such as whether a machine or application is online or not. Be cautious of using icons that depend exclusively on color to differentiate state, as 10 percent of the Copyright © 2005 BrightPoint Consulting, Inc. www.brightpointinc.com male population and 1 percent of the female population is color-blind; consider using shapes in conjunction with color to differentiate state.

2. Traffic Light Icons: The traffic light is a simple extension of the alert icon, and has little advantage over the alert icon in terms of data visualization. Like the alert icon, this component only offers one dimension of information, but it requires 300 percent of the screen real estate. The one advantage of the traffic light icon is that it is a more widely recognized symbol of communicating a “good state”, “warning state” or “bad state.”

When to use: In most cases a simple alert icon is a more efficient visualization, but in situations where your dashboard is being used by a wide audience on a less frequent basis, a traffic light component will allow users to more quickly assimilate the alert information due to their familiarity with the traffic light symbol from real world experience.

3. Trend Icons: A trend icon represents how a key performance indicator or metric is behaving over a period of time. It can be in one of three states: moving toward a target, away from a target, or static. Various symbols may be used to represent these states, including arrows or numbers. Trend icons can be combined with alert icons to display two dimensions of information within the same visual space. This can be accomplished by placing the trend icon within a color- or shape-coded alert icon.

When to use: Trend icons can be used by themselves in the same situation you would use an alert icon, or to supplement another more complex KPI visualization when you want to provide a reference to the KPI’s movement over time.

4. Progress Bars: A progress bar represents more than one dimension of information about a KPI via its scale, color and limits. At its most basic level a progress bar can provide a visual representation of progress along a onedimensional axis. With the addition of color and alert levels, you can also indicate when you have crossed specific target thresholds as well as how close you are to a specific limit.

When to use: Progress bars are primarily used to represent a relative progress toward a positive quantity of a real number. They do not work well when the measure you want to represent can have negative values: The use of shading within a “bar” to represent a negative value can be confusing to the viewer as any shading is seen to represent some value above zero regardless of the label on the axis. Progress bars also work well when you have KPIs or metrics that share a common measure along an axis (similar to a bar chart) and you want to see relative performance across those KPIs/metrics.

5. Gauges: A gauge is an excellent mechanism by which to quickly assess both positive and negative values along a relative scale. Gauges lend themselves to dynamic data that can change over time in relationship to underlying variables. Additionally, the use of embedded alert levels allows you to quickly see how close or far away you are from a specific threshold.

When to use: Gauges should be reserved for the highest level and most critical metrics or KPIs on a dashboard because of their visual density and tendency to focus user attention. Most of these critical operational metrics/KPIs will be more dynamic values that change on a frequent basis throughout the day. One of the most important considerations in using gauges is their size: too small and it is difficult for the viewer to discern relative values due to the density of the “ink” used to represent the various gauge components; too large and you end up wasting valuable screen space. With more sophisticated data visualization packages, gauges also serve as excellent context-sensitive navigation elements due to their visual predominance within the dashboard.