Red Light, Green Light

Red Light, Green Light

One of the most common indicators used in measurement and status report are traffic light indicators.  Traffic light indicators have been adopted because they are easy to recognize, represent complex information in a palatable manner and indicators are easy to explain.  The traffic light is elegant in its simplicity; however, that simplicity can also be its undoing. There three critical issues that traffic lights often exhibit which reduce their usefulness.

  1. Traffic light indicators obscure nuances and trends. Traffic light indicators generally use the simple green, yellow and red scale (good to bad). The indicator can only be set to one of those states, and there is no in-between (no orange or greenish yellow). HOWEVER, project status is rarely that cut and dried. For example, how would the indicator be set if a project exhibits serious threatening risks but the stakeholders currently satisfied with progress? Regardless of whether the indicator was set to red or yellow, much of the nuance of the situation would be lost. In addition, the traffic light indicator could not show whether the risks were being mitigated or threatening to become issues.
  2. Traffic light Indicators can generate poor personal and team behaviors. One of the most common problems observed with the usage of traffic light indicators is sticky statuses. A status is green or yellow, then seems to suddenly turn yellow or red overnight. The change from one color to another typically surprises management and stakeholders.  The change of color/status is often resisted because a change is viewed as a failure since there is no mechanism to provide a warning making the change is resisted. A second common problem is that making the indicator change becomes the project leader or team’s most important goal. When the metric becomes the goal, individuals and teams can be incented into trying to game of the metric which removes the focus from the customer.
  3. Traffic light indicators can lead to users of the indicator losing track of how it was calculated. Any high-level indicator, like a traffic light indicator, is a synthesis of many individual measures and metrics. Meg Gillikin, Deloitte Consulting, suggests “that you should have definitions of what each state means with specifics.”  The users of the indicator need to understand how it is set and the factors that go into setting the metric.  Lack of understand of any indicator can lead managers into making poor decisions…

Dácil Castelo, Leda MC, sums up the use of traffic light indicators, “The use of red, green and yellow provides a quick, visual summary of the status in a simple and easy way (everyone knows what a traffic light is). On the other hand, easy to understood doesn’t mean easy to calculate nor necessarily useful for the user.” Remember that with any indicator there is a basic issue IF an indicator doesn’t actually help teams and leaders to delivery of value it will be view as overhead

Stop on Red!

Stop on Red!

One of the most common indicators used in measurement and status report are traffic light indicators.  Traffic light indicators are most commonly shown as a set of red, yellow and green lights.  The metaphor draws from the nearly ubiquitous traffic light seen at nearly every intersection.  Traffic light indicators are part family of indicators of that combine indices and scales. Indices are typically used when a single measure or metric does not tell the story. An index reflects a composite of measures. Measures and/or metrics are averaged together or combined using complex mathematics.  The index is then transposed onto a scale so that it can be interpreted and used.  For example, wind chill is an index that combines temperature and wind speed into a temperature perceived by the skin. Wind chill once calculated is shown on a temperature scale. As a project status indicator, a traffic light indicator typically reflects a synthesis of many attribute.  The traffic light uses a simple scale in which red means trouble; yellow means caution and green means clear sailing. Traffic lights are adopted for three highly related reasons.

  1. Traffic lights are easy to recognize. The traffic light is a common symbol that every driver has been taught to recognize. Attaching a traffic light instantly indicates that a summary of status is being communicated.
  2. Traffic lights provide a consolidated view of complex attributes. The traffic light scale is a simple metaphor with three possible indications of overall performance.  Even in a simple project attributes such as budget, client satisfaction and risk must be synthesized into single perception of status that can be communicated. Traffic light indicators force a synthesized view.
  3. Traffic lights are easy to explain. Once an organization reaches a consensus on the business rules that set a traffic light indictor to red, yellow or green, is easy to explain. Red is bad and requires immediate action, yellow means caution, performance issues require mitigation and green mean business as usual.   Paul Byrnes, CMMI Lead Appraiser, when asked why people are drawn to traffic lights noted that “colors are easy…except for people that can’t see them… .”

 

Karl Jentzsch, a colleague at David Consulting Group summarized the case for traffic light indicators as “the appeal is that it provides an easily manageable number of ‘buckets’ to drop things into where the categorical distinctions are still fairly clear and inherently understood – good/go (green), bad/no (red), and in between (yellow).”

I often hear traffic lights defended with the statements like “we have always used traffic lights” and “or they are required by the PMO.” These are excuses that reflect an abrogation of thought and responsibility. It is too easy to succumb the simplicity of the indicator without reflecting on all the hard work and analysis needed to set the indicator. Typically this should be a lot of math and analysis to set the traffic light to red, yellow or green.  The math and the analysis is where the real magic happens and requires thought and understanding. As an indicator, the traffic light is elegant in its simplicity; however that simplicity can also be its undoing.