Variability is defined as “a lack of consistency or pattern” or “liability to vary or change”. In business procedures, effects like fluctuations in task size and type, unreliable equipment, sick or unreliable workers, raw material and supply fluctuations, and many others can contribute to variability. Given the complexity of most processes, it’s not surprising that many of these factors multiplied can add up to a large amount of randomness.

What took 2 days to complete last week, might take 4 days to complete this week! Variability in time from one step of a transaction to another can result in backlogs. Within the process, priority orders may end up waiting for parts while non-priority orders sail through. This makes accurate scheduling almost impossible and can result in serious customer service problems.

How can we deal with variability? First, we must realize that there is no way to eliminate variability in a process, we simply reduce it. Begin by discussing the topic with the people who perform the tasks. Ask them what causes them the most frustrating delays. It’s likely that the more you talk to them the more a pattern will emerge, with a handful of continuous root causes. If you can identify these root causes you can begin to attack those issues. Begin by looking at the progression steps and determine what is the bottleneck and use the “5 Whys” to help identify root causes.

Variability can also be mitigated by being flexible with your processes. If delays are inevitable at one step, try to make sure that the system is flexible enough to allow a task to move to another step that isn’t being delayed. Cross-train employees and make sure that bottlenecks and delayed steps get priority staffing. Combining steps as much as possible can also help reduce variability. This reduces the complexity and consequently reduces the potential impact of variability on that process. If necessary, expand your capacity at steps that are subject to high variability.

Next time you end up in a long line at a checkout counter, you may want to think about variability in your own business. Do you know what transactions have large variability? Do you know what the causes of that variability are? Getting consistent, measurable results from your efforts from your processes can help prevent your products from ending up in line like you!

By Tony Yoder, CPTO