Steps in the Control phase
– In my experience, losing weight is easy. Keeping it off is hard. I start eating right, exercising right. But when holidays come along, all bets are off. And all of the improvements I’ve made are no longer sustainable. You don’t want that to happen to your project. Now, that your Six Sigma project team has improved the Y. How do you ensure that a new performance level is sustainable? That’s why you need the control phase. The main purpose of this phase, is to establish controls. The control the key X factors to ensure the improved Y is sustained on an ongoing basis. Sustainable after the conclusion of the project and the disbanding of the project team. In other words, the project team does not need to babysit the improved process. The five steps in the control phase are: First, develop a control plan for, monitoring, controlling, and regulating performance. The control plan tells when to leave a process alone and when to take action and what action to take. For example, there’s a control plan under the hood of your car. The oil dipstick has markings to indicate when you should add oil and if you are low, how much oil you need to add. Such controls must designed for use, by process owners and operators who carry out the process routinely. Day in and day out. Here is another example, say the desired temperature in the room is 72 degrees Fahrenheit, the control plan should specify the desired temperature and who’s in charge of regulating the temperature. And when are they authorized to take action and what action to take. In this example, someone in the room is assigned the responsibility and given the authority to regulate temperature. The control plan specifies: Increase the temperature if it drops below 70 degrees, and lower the temperature if it goes above 74 degrees, in between do not adjust. The next step in a control phase is to work with process owners to update procedures, which incorporate the controls and implement communication and training plans. Then, implement with the process owners and monitor performance. Once, project improvement goals have been achieved, finance will validate the actual financial impact. Finally, project completion is signed off by the project champion. Now, you can celebrate success. Mission accomplished. The control phase is technically the easiest of the five phases. But organizationally, the most difficult. Once you and your team leave, the people inheriting your work need the right tools in place to sustain the new performance level.
How to use SPC charts
– After all the hard work we’ve done, how can we monitor performance levels? I have the chart for you. It’s called the Control Chart or SPC Chart. What does SPC stand for? SPC stands for Statistical Process Control. Don’t let the name scare you. The purpose of the control chart or SPC chart, is to indicate to you when to leave the process alone and when to intervene and troubleshoot. Why? So that you don’t react to random variation. Regardless of how well designed the process is, there will always be some variation. And even under the best operating conditions. That variation is random variation. You experienced random variation every day. For example, when you go to work in the morning. Let’s say your commuting time averages 30 minutes. Some mornings, it may take you 25 minutes, and other mornings, 34 minutes. Nothing special happened. Should you change your route as a result of this random variation? No! You don’t want to react to random variation that is inherently present in every process. However, if it’s gonna take you an hour to drive to work because of a jack knife tanker truck on the highway, then you will want to intervene and take action. Once you are alerted to this accident, you want to detour, change your driving route, or better yet, take the morning train. That is what a control chart, or SPC chart does. Using statistics to indicate when it is random variation, and when it is not. The SPC chart tells you when to leave the process alone, because it is just random variation, and when to intervene and take action because something out of the ordinary happened. What a great signaling tool. Let me add some historical context so you will understand its purpose and why it is useful. SPC charts were developed back in the 1920s by Dr. Walter Shewhart. He was in charge of quality control in the Western Electric Factory making telephones. If there was a problem on the production line, the line had to be stopped to address the problem, however, each time the line was stopped, fewer phones were produced that day. It’s okay if it was a real problem, but it is very expensive if the decision to stop the line was wrong, and it was just random variation, and not a real problem. So Dr. Shewhart developed a tool called control charts to provide the correct signal as to when it is random variation and when it is not. The signals enable management to know when to take action, and when to leave the process alone. His charts were later called statistical process control or SPC charts, so there you have it. There are SPC charts for continuous measurements, such as dimensions and time, and there are SPC charts for counts of defects and proportions. Whether your process is producing products or processing a transaction such as an invoice, SPC charts are applicable to provide signals to the process owners on when to take action and when to leave the process alone. Implement SPC charts during your control phase. Don’t react to random variation.
The control plan
– How often is the temperature in your office not quite right? Maybe it’s too hot or too cold. Who decides? By the way, what is the desired temperature? When is it too cold, and when is it too hot? And who is authorized to change the temperature? There is a tool to help you answer all those questions. It’s called a Control Plan. The Control Plan is a blueprint for ensuring the right controls are implemented to achieve performance targets on a sustainable basis. It provides process owners and operators with a means to control a process so that it performs well day-in and day-out. That is why the Control Plan is so important during the Control Phase of Six Sigma project. The Control Plan specifies One, what needs to be controlled. What needs to be controlled is called the Control Subject. Control Subjects should be the Relevant Y and any key X Factors. In our office example, the Control Subject is temperature. Two, the specification, target, or desired range. We can specify the target as 72 degrees Fahrenheit. And it is too hot when it is above 75 degrees. And too cold when it is below 67 degrees. So the desired range is 67 to 75 degrees. Three, how feedback on actual performance is provided, including how the measurement is made, how frequently, and where it is recorded. In our example, using our room thermometer, read by someone assigned that role, the temperature is to be checked and recorded every hour. Four, when to take action and what action to take. Leave the temperature alone when it is between 67 and 75 degrees. Take action as follows. When the temperature is above 75, turn on the AC. When the temperature is below 67 degrees, turn off the AC, and if needed, turn on the heat. Five, who is responsible and authorized to monitor and take action. In our example, we can state that the person assigned is responsible for temperature and is authorized to take action, and specify that results and actions taken should be recorded. To summarize, a Control Plan specifies what needs to be controlled, the specification, target, or desired range, how feedback on actual performance is provided, when to take action and what action to take, and finally, who is responsible and authorized. With a Control Plan embedded in standard procedures and operating instructions, the folks running the process have the ability and the means to control the process, so that it performs well, day-in and day-out. Now that we have a Control Plan down, nobody in your office should ever shiver or sweat again.