In my previous blogs, I describe the framework around how to manage a project, the process groups and we started with the three well-known knowledge areas of Scope, Schedule & Cost. I now continue with one of my favourites, Quality.
Everybody wants Quality and it’s an important metric in the end-user’s experience with a product. But what is quality? How do we measure it and how do we go about improving it?
Quality can be defined as the number of defects against the specification. In software, the number of bugs in the code. In manufacturing, the deviation from the defined tolerances. It is important to separate it from Grade which is the “ability of the product”. For example, if I purchase a new mobile phone, I can buy a phone with just call functionality (low grade) or I can opt for the latest smartphone with a touchscreen and Internet access (high grade). In both these cases, I choose the brand on it’s quality or the ability for it to do what the manufacture says it does without defects. As Project Managers, we aim for perfection in quality, but low-grade is not always a bad thing. In fact, creating a high-grade product when the specification asked for one of low-grade is a real issue.
Seven Basic Tools
How do we measure quality? The PMBOK defines seven basic tools. Of course, there are many more, but these seven will enable you to analyse most situations:
* Ishikawa (or fish bone) – We use an Ishikawa diagram when we wish to understand the root cause of a problem. It is called a fish-bone as the problem is drawn as a central spine and the causes are “bones” off that spine. The process is to brainstorm the question “Why this happens?” To get things started, 6 possible areas are usually defined: Methods, Machine, People, Materials, Measurement, Environment. For each cause, you would then continue the brainstorming, again asking the fundamental question “Why this happens?” For example, our wall is unstable. Why? Because the bricks are inferior. Why? Because they were cooked at the wrong temperature. Why? …. After the brainstorm, we will have a number of root causes that we can then directly tackle. (This technique was developed within Lean Six Sigma as the 5 Whys)
* Checklists – Checklists are an extremely useful tool for preventing errors from occurring. Probably the most well-known is the aviation’s pre-flight checklist. Such is the confidence in these checklists that I doubt anybody would want to fly in a plane if before the flight the Captain announced they were skipping the checklist. They are useful for junior and experienced team members alike. They inform the junior engineer of important things to check and stop the experienced team member from getting complacent. They are an important feature of Sondrel’s Neon methodology.
- Control Charts – Used to study processes over time. For example, if I’m manufacturing a steel bar to a specific length, I would perform spot checks on the manufacturing and record the length of the bar at each inspection. From this I could determine if my process was in-control. If not, I would attempt to improve the process and use the control chart to determine if the improvement had the desired effect.
- Histogram – Used to record the frequency distribution of sampled data. Suppose we conducted a customer satisfaction survey. We asked 100 customers what area of our service most needed improving. We would record this information on a histogram, with a bar for each response category. In the next survey, we could then compare which areas were getting better or worse.
- Pareto Chart – A Pareto Chart is a form of histogram, but we order the categories in descending frequency. This aids us in determining which area to tackle first. We also draw a cumulative line to show the total frequency of issues to the left of the chart. In this way it is clear which of the issues we need to address first and how many issues we should address to achieve our goal.
- Scatter Diagram – Used to record the relationship between two numerical values. For example, we could modify the amount of carbon in a steel bar and then test its breaking load. Plotting the carbon amounts versus the strength will reveal if there is any relationship between the two.
- Stratification Diagram – A Stratification Diagram is a form of Scatter Diagram but with multiple data sets. Suppose we were to perform our carbon/load experiment but find no relationship (which would be highly questionable). We could repeat the experiment but have different datasets for different manufacture machines. This could show us that one machine was adding in random effects that were confusing our results.
Lean Six Sigma
We have the tools to measure Quality but how do we improve it? Only briefly mentioned in the PMBOK but I can’t write a blog on Quality without saying something about Lean Six Sigma which is a synergized managerial concept of Lean and Six Sigma.
Lean was developed in post-war Japan by Toyota. It was driven by the fact that supplies and warehouses were in short supply and therefore all waste (muda) in the system needed to be eliminated. It has 5 main pillars:
- Value – Know what the value of your product is. It’s no good creating features that the customer doesn’t want. You need to listen to the Voice of the Customer
- Value Stream – For all the processes in your company, know which of those add value to your customer. For example, manufacturing of the product creates value but transporting it from your warehouse to the customer does not. There are two types of muda: type 1 that does not add value but can’t be completely eliminated, and type 2 which is pure waste and should be removed. For example, some form of transportation from your depot to the customer is almost always going to be needed. This is type 1 muda. Defects caused by poor machining are type 2 muda.
- Flow – The route that a product takes through your processes should be analysed and inefficiencies removed. Frequent stops and starts to change equipment configuration are the prime example of poor flow.
- Pull – The customer should “pull” the product through your process i.e. the order generates the product, which generates the part which in turn generates the raw materials. The alternative “push” relies on inventory to cope with demand which is a form of muda.
- Perfection – Never stop improving, it not good enough to be just better than your competitors, you must always be improving.
- Define – We state the problem
- Measure – We create a baseline of the current situation e.g. with control charts
- Analyse – We analyse the root cause of the problem e.g. via an Ishikawa diagram
- Improve – We identify, test and implement a solution to the problem
- Control – We monitor the improvements to ensure the gains are sustained e.g. back to the control chart
Six Sigma was invented by Motorola in the 1980’s to compete with the Lean model. It aims to systematically identify and remove the root causes of defects in the manufacturing process. Why Six Sigma? Because if a process has a six sigma variability then only 1 defect occurs in approximately 500 million products.
In short, Lean exposes sources of process variation and Six Sigma aims to reduce that variation enabling a virtuous cycle of iterative improvements towards the goal of continuous flow. Lean Six Sigma uses cycles of continuous improvement known as DMAIC cycles (pronounced dee-may-ik). For each problem we:
This is an insight into the knowledge area of Quality. We understand the difference between Quality and Grade, have seven tools to measure quality, and now have a framework for analysing, improving and sustaining our quality process. In the next blog, I will continue our examination of the knowledge areas with the Human Resources knowledge area.
Andrew Miles PMP
Andrew Miles is a physical implementation engineer turned project manager. He is PMP certified and has led many projects for a number of tier one companies. He helps to run the Sondrel Project Management Office (PMO). If you'd like to know how Sondrel's project managers can help your project then please contact email@example.com