For people in the world of statistics, one of their most inspiring discoveries is that of the bell curve and how it applies to the world in which we live. Basically, everything on earth, and possibly in the universe falls, statistically, into some version of a bell curve. For example, if I were to plot a histogram of my golf scores over the past five years, there would be a mean of the scores which would be the highest number (top of the bell) and then two tails of higher and lower scores.
So everything from the number of cups of coffee you drink each day to the variance of IQ scores will fall into some distribution of a bell curve. Itwould be safe to assume that quality items or as they are called, defects, will also follow this same distribution either in manufacturing or construction.
So what Six Sigma intends to do is take the number of defects in a particular process down to six standard deviations away from the mean (middle of the curve). Basically, this amounts to 3.4 defects per million opportunities (DPMO).
*Note: Six standard deviations from the mean would actually be about two hundred times less than 3.4 DPMO, but there is some theoretical shift of 1.5 sigma that occurs in the calculation that may or may not be legitimate and I don't really understand it. In either case, 3.4 or 0.015 DPMO is pretty damn good for a construction project so for all intents and purposes the difference is negligible.
So this is a nice little goal to set for yourself, but how might one go about reaching this pinnacle of quality? Six Sigma projects follow two project methodologies comprising five phases each with the acronyms DMAIC and DMADV.
DMAIC is used for projects aimed at improving an existing business process.
DMADV is used for projects aimed at creating new product or process design.
The DMAIC project methodology has five phases:
Define high-level project goals and the current process.
Measure key aspects of the current process and collect relevant data.
Analyze the data to verify cause-and-effect relationships. Improve or optimize the process based upon data analysis. Control to ensure that any deviations from target are corrected before they result in defects.
DMADV
Define design goals that are consistent with customer demands and the enterprise strategy.
Measure and identify CTQs (characteristics that are Critical To Quality), product capabilities, production process capability, and risks.
Analyze to develop and design alternatives, create a high-level design and evaluate design capability to select the best design.
Design details, optimize the design, and plan for design verification.
Verify the design, set up pilot runs, implement the production process and hand it over to the process owners.
My keen intuition tells me that construction projects will fall into the DMADV because every construction project is different. Which brings us to the main obstacle of implementing Six Sigma on a construction project: Construction is not manufacturing!
Six Sigma was developed by Motorola to improve quality. Companies like Motorola have the luxury of having design and manufacturing all in house and not to mention the fact that they are building the same thing over and over. Imagine trying to put an automobile together when it is not only a unique design, but every part of the car is installed by a different company! And then implement a quality management system for every unique installation that came down the line.
Construction isn't quite that difficult because you are working on a much bigger scale but we have to realize that implementing manufacturing principles into construction is just not that easy. Plus the whole Six Sigma black belt certification process is a little cheesy. However, a six sigma level of quality is nothing short of a fantastic accomplishment.
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I had a client, on a huge township project, who was all excited about 6 Sigma. It is not easy to translate to construction because we manufacture one offs (mostly).
ReplyDeleteTo fulfill the client's goals we approached, not the individual buildings, but the building process as DMAIC. The most fruitful part of the 6Sigma excercise was the defining of quality in our process, instead of in our product.
Each department's internal process was fine in their opinion, but we had to scruitinize all yhe other departments.
In the end we set up some parameters for confluent activities like subcontractor payments (where accounting, field, project management, risk management and finance came together) developed expectations, metrics and a feedback loop on the process. We had about 5 of those going when I left the project. The processes were definitely improved.
If consistently expanded over the life of the project they may finally acheive a 6Sigma process in all aspects of the work. The question would be how long would it take to get to quality in the constructed item and is there an easier way.
Just my thoughts on my experience.
Six Sigma is all hype. Basically, some management consultant repackaged statistics ( and also charged big $$$ dollars for doing it) with new supposedly easier to understand nomenclature and called it "Six Sigma" - statistics for dummies . The essence of Six Sigma is to numerically quantify improvements, which is something any company can and should do on their own.
ReplyDeleteFrom my experience with Six Sigma on construction projects is that the time it takes to develop the "mindset" to understand Six Sigma time is lost and costs incurred that should have been used to evaluate the process without calling it Six Sigma. Since most individuals in the construction industry already have a technical background and understand statistics to begin with, Six Sigma is best left for those industries managed by those without engineering backgrounds.
Six Sigma is only one of many tools available that the construction industry (and AEC as a whole) needs to embrace. I think the only industry lagging behind in technology, innovation, and progressiveness is real estate!
ReplyDeleteI find it amazing that so many problems in the industry are caused by business processes, and not technical issues. Think about it - communication is always at the top of things "others" could do to improve consturction. That feeling extends from a lack of process, controls, and procedures within the business entity and rarely has much to do with the "construction" portion.
It's too bad that there are more "Steven" type people out there than Mr. Burkhardts.
As a certified Lean Sigma Black Belt, it's implementing and sustaining a process that makes or breaks a teams initiative.
ReplyDeleteTime and time again, teams gather data and make great strides at improving processes, but they seldom sustain those advancements.
Remember, change is not an event, it's a culture.