- Stoplights are not progressive. Project stoplights typically have only three indications of status. They can't show a range of progressive tolerance, trends or rates of change. For example, a yellow stoplight can be overly optimistic if the value for that stoplight is just shy of the range for red.
- Stoplight bands mean different things to different measurements. Stoplights break down into bands of tolerance ranges. For example, zero to 5 percent variance would be green, 5 to 10 percent variance would be yellow and above 10 percent would be red. The problem is, project measurement indicators might not follow a common range. For example, how realistic is it to measure customer satisfaction with the same band as test case validation? While test case validation might make sense at 7 percent, it would be discouraging if just 7 percent of your customers were happy with your project.
- Stoplights can be "gamed." A major vulnerability of project stoplights is that they can be manipulated by project managers and sponsors when either wants to defer an unfavorable status. Despite the actual value of the project measurement, the project manager or sponsor will leave the stoplight to a green (favorable) value. This "gaming" of project stoplights usually precedes the inevitable -- rapid acceleration of stoplights to a red (danger) value when hidden details are discovered.
Three Reasons to Dim Project Stoplights
The views expressed within the PMI Voices on Project Management blog are contributed from external sources and do not necessarily reflect the views and opinions of PMI.