Once you've used Six Sigma methodology to define, measure and analyze your process, you come to the improve and control steps of the DMAIC process. It is at these steps that true improvement action is taken, and this is where SMART statements become effective at guiding both goals and objectives for process improvement.
The SMART Acronym
Using SMART to guide goal and objective development is not unique to Six Sigma methods. It is commonly used as a tool in project management as well as other best practices, lean and continuous improvement programs. The acronym stands for Specific, Measurable, Attainable, Reasonable and Time-bound when used with action items for a Six Sigma program. Your SMART statement serves as a summary of each aspect of your goal.
As an example, consider that a problem is found with a high rate of defective parts coming from a particular manufacturing process. The goal is obviously to reduce defective parts, but that in itself doesn't pinpoint what will be accomplished. Perhaps the part has an occasional stamping defect, and this defect frequently gets past quality inspectors. A specific SMART statement might start "Reduce stamping defects" for the part in question.
Measurability is key to the statistical data-gathering central to the Six Sigma ideal. It is tangible evidence of progress toward a goal. Measures can be amounts, ratios, deadlines or anything else that can be assigned an observable and comparative value. Using the defects example, measurability in the SMART statement could be the value of "defects per 1000 parts."
If performance is currently at 120 defects per 1,000 parts while your target is 1 per 1000, the goal may not be reasonably achievable. Making targets reasonable helps sustain impetus while building a culture of improvement. Setting an initial target of 100 defects per 1,000 provides a workable number that represents progress but doesn't overreach. The SMART statement for this example now reads "Reduce stamping defects to 100 defects per 1,000 parts."
Installing a new stamper may accomplish the target in a single step but it may not be reasonable if the stamper costs $250,000 while the defects account for $10,000 in waste. Adding constraints or methods to a SMART statement contains the scope of an action toward improved performance. Addressing stamper maintenance may be a reasonable approach, so the SMART statement continues "Reduce stamping defects to 100 defects per 1,000 parts by increasing preventive maintenance cycles."
Binding a SMART statement to time gives a deadline for not only completing the goal or objective but also periods for interim progress measurement. An open-ended plan of action has no urgency or any momentum created through partial achievement. The defects example uses time also as a frequency measure to identify the reasonable effort. The complete SMART statement for defect reduction states, "By the end of the third quarter, reduce stamping defects to 100 defects per 1,000 parts by increasing preventive maintenance cycles from biweekly to weekly, while reporting defect rates monthly."