The Six Sigma project here was deployed three years ago. Yet the lessons to be learned from it still apply to this day.
The aim was to reduce the cycle time of submitting error-free monthly reports by the accounting department. Top management puts a Six Sigma team to do the task. Part of the task would be to identify the need for the project, the costs and benefits, the resources required, and the time frame. The team gathered that management wanted a monthly accounting report to be completed in seven days and that the report should never be completed in less than four days and never later than 10 days. Team members identified the project charter as
follows:
Reduce (direction) the variability in the cycle time (measure) to produce an error-free accounting report (process) from the current level of seven days plus or minus three days to seven days plus or minus a half-day (target) by January 10, 2002 (deadline).
To be able to do this successfully, the team knew that they needed to apply the DMAIC model.
At the Define Phase, the team prepared a business charter, found out the relationships between suppliers-inputs-process-outputs-customers (SIPOC), and gathered and analyzed ?Voice of the Customer? data to identify the Critical to Quality (CTQ) characteristics important to customers.
At the Measure Phase, the team developed operational definitions for each CTQ variable, performed studies to establish the veracity of the measurement procedure, and then established baseline capabilities. This is how the team did it.
First, the members of the Six Sigma team defined ?variability in cycle time? such that all relevant personnel agreed upon the definition. Second, they performed a study to determine the veracity of the measurement process. Finally, the team members collected baseline data about variability in cycle time, and statistically analyzed it.
At the Analysis Phase, the team then identified upstream variables (X) for each CTQ; operationally defined, collected baseline data, performed studies to determine the veracity of the measurement process, and established baseline capabilities for each X; and went on to understand the effect of each X on the CTQ. Team members identified all input and process variables that affected variability in cycle time, known as X. This activity, referred to as process mapping, included flowcharting.
The Improvement Phase involved designing experiments to understand the relationship between the CTQs and the Xs, determining the optimal levels of critical Xs that minimize variability in the CTQs, developing action plans to implement the optimal level of the Xs, and conducting a pilot test of the revised process.
And at the Control Phase, the team avoided potential problems with the Xs in risk management and mistake-proofing, standardized successful process revisions, put control to the critical Xs, documented each control plan, and turned the revised process over to the process owner.
The process owner in turn needed continue to work toward improvement, that being the distribution of days to produce the report. This translated to a report being early or late about once every 24,500 years.
Tags
accounting
VOC
CTQ
DMAIC
