Create Realistic Specifications using RUMBA in your Six Sigma Projects

A mind-jogging acronym, RUMBA, is used in Six Sigma to support you assess the suitability of any specification:

• Reasonable: Is the specification based on an accurate assessment of the customer’s actual requests? Does the specification relate directly to the performance of the characteristic?
•  Understandable: Is the specification clearly stated and defined so that there can be no argument about its interpretation?
•  Measurable: Can you measure the characteristic’s performance against the specification? If not, there will be a lot of debate between you and your customer as to whether the specification has been met or not.
•  Believable: Have you bought into the specification setting? Can you and your co-worker peers strive to meet the specification?
•  Attainable or achievable: Can the level and range of the specification be reached?

Very often, an improvement project is fast-tracked or resolved through a simple evaluation and adjustment of the involved specifications. The performance of the characteristic or process never has to be altered. Constantly review the appropriateness of specifications early in your Six Sigma project.

Specifications should never be arbitrary. Except they essentially represent the values that separate good from bad performance, they become a stumbling block to evolvement. If a specification is set too sloppily, your customer will be disappointed or upset with the performance of what you provide — even though it meets its requirement. If a specification is set too tightly, you devote more resources than you should to always perform within your excessively narrow goalpost.

You need to review each specification to make sure that it passes the RUMBA test. If it falls short in any of the RUMBA categories, begin to cultivate a plan to bring the rogue specification back into control.