Project Management: What are Control Charts Vs Run Charts?

Control Charts and Run Charts are among Severn Basic Tools of Quality. The appearance of control chart and Run Chart are similar so they tend to create confusion some time.

Recently, I see this discussion in a popular PMP Forum. The healthy discussion did inspire me to write the differences and similarity between Control Chart and Run Charts.

Control Chart	Run Chart
Control Charts are used to check how a process is performing. Control Chart will tell you whether a process is under CONTROL or OUT OF CONTROL.	Run Chart are use to show and depict process trend. It helps to predict future trends.
Control Charts has a UCL (Upper Control Limit), LCL (Lower Control Limit), Mean on the chart	Run Chart has only two axis – one axis shows time/time-scale and second axis shows the events. It depicts whether a process is trending upwards or going downwards.
Example: ECG reports	Example: Stock trends, Run rate graph, Error Rate of a employee
It is also called "Shewhart Chart" or "Process behavior Chart"
Control Charts were invented by Walter A. Shewhart

Image Source: Wikipedia

Next: What is XMR Chart

Project Quality Management What is Quality?

“Quality” is one thing that everyone desire to have in their personal and professional life. It is one single thing that you constantly look for whether you are shopping, dating, working or just relaxing. A popular phrase is “What is common between a Lion and a Chef?” – The answer is Quality. Lion or chef will never compromise with their food quality. It does not matter how hungry the Lion is, he will never eat grass or vegetarian food. The same apply to the Chef.

So the point is Quality is looked upon in every activity that we do. But do we know, what is the Quality that we often hear in the meetings? This article is for the beginners who want to understand what is quality, where it is coming from, how to measure this etc.

It does not matter whether you are working on a product based or project based module, you always hear about project leads and project managers talking about quality?

What is Quality?

Quality is the degree or parameter to which you fulfill the customer requirement. If customer wants to paint the building in deep aqua color and you are delivering it, you are fulfilling the customer need and giving him quality. It may look odd to the rest of the world, but be assured you are producing quality for your customer.

In the world, Quality is always and always looked from Customer prospective. If customer is happy with the project outcome, you have given him quality work.

One basic thing that you should always remember is:

Quality is always and always measurable. As a project team member, the quality you are delivering can be measured and compared every time or any time.

What is the source of Quality?

Whenever a product or project is initiated the customers always express their requirement in a very simple and generic term. Take some example of requirement;

• A car manufacturer wants to develop a car and wants its cabin to be cool in all temperatures.
• A customer wants his website to load fast on all devices.
• The system should be able to handle all transactions generated.

These project or product requirements examples are simple or say subjective in nature. Quality requirements are not given by customer directly; it is project manager or project team that has to pick the quality requirement from the given subjective customer requirement. The above examples are example of subjective requirement. So as a project manager or project team these are your Quality requirement for the project or product you are working upon.

Do you think, for the requirements like above, you will be able to provide quality to the customer? — My answer is NO. Why?

The reason is if you cannot measure quality, you can claim that you have produce quality. For example, the website load time will be vary with the different internet connection speed. So you have to think following scenario in this situation.

• What should be the website load time on slow internet connection (100KBps speed)?
• What should be the website load time on internet connection (500KBps speed)?
• What should be the website load time on internet connection (2MBps speed)

A Project manager or project team has to discuss the above scenario with client. The website home page will take different time to load with different internet connection speed. You have to provide different time range for each of the internet connection speed. For example, you can set up 20 to 50 seconds load time for internet connection speed of 100KBps. Similarly, you can set up 10 to 40 seconds load time for internet connection speed of 1MBps. When you are doing this with your project and customer, what you are doing is – you are setting up Quality Goal for the Quality requirement.

What we do during the Quality goal setup is we are converting the Subjective Quality requirement into Objective Quality requirement. For each of the quality requirement you set up quality goals. A single Quality goal may be applicable to multiple Quality requirements. Each of the quality goals has a name, description and a client acceptable range.

OK, so you have picked up the quality requirements out of project requirement and setup quality goals for each of the quality requirement. What is next?

The next thing is how you are going to achieve the Quality Goals that you have setup for the project or product. The answer is Quality Standards. Quality standards are set of rules and guidelines that help the project team and project manager to achieve quality goals. Do you peer review the design or code in your project, if yes that is an example of Quality standards that you are applying in your project.

As a project team or project manager you have to specify what quality standards you will be using in your project. The example of Quality standards includes coding standards, checklists, templates, procedures, guidelines etc.

So the story for Project Quality Management starts with collecting Quality requirement, setting up Quality Goals and Quality standards for the project. What is next? I will cover this in next topic. Till then thanks for reading this post and please let me know your valuable suggestions, feedback on this.

Related Article:

• Project Quality Management: What is Quality?
• What is XMR Chart?
• Do you care for your Communication Style?
• Do you care for your Visual Communication Style?
• Do you care for your Kinesthetic Communication Style?
• How to improve your V.O.I.C.E?
• PM: How accurate is your Project Cost Estimates?
• PM: Do you know your Project Cost?

What is XMR Chart?

What is the one thing you desire most when you are dinning with family in a popular food joint? Quality or simply food quality, right? What is it that you look when you are buying a gazette or dress or anything for which you are paying from your pocket? Is it Quality? Yes, that is right…it is the quality that you look for in everything your buy or pursue.

How do you know or measure quality in the products or services you are delivering to the client? How do you know your processes are working as you expected? There are tools available to measure the qualities. There are Seven popular qualities tool available which are used worldwide to measure or observer the qualities in various industries such as IT, manufacturing, Publishing etc.

These 7 basic tools of quality are following:

1. Ishikawa diagram
2. Check sheet
3. Control chart
4. Histogram
5. Pareto chart
6. Scatter diagram
7. Flow chart

Today I learn about one of the quality tool called XMR chart. XMR stand for X – Individual and MR – Moving Range i.e. Individual and Moving Range Chart.

When XMR chart was invented?

The control chart concept was introduced to the world by Honorable Mr. Walter A. Shewart. He proposes this while working for Bell Labs.

So what exactly is XMR Chart?

XMR or I-MR chart is type of Control chart. This chart is used to observe or monitor one single data item. This single data item can be anything such as individual salesman productivity, an employee attendance or a production support team ticket resolution time etc. The single data item can be observed or monitored on weekly, monthly or yearly basis.

XMR is a type of Control Chart which is used for observing single data point. In other words XMR chart is use to observe one single item in a given time period or in a given data range.

The second important consideration about XMR chart is that data points are independent of each other. By observing one data point you cannot predict what the next data point will be. In other words by observing productivity of one day of an employee you cannot say what the productivity will be next day.

XMR Moving Range observes differences between data points. The range of the data points could be either the two (consecutive data points) or more. The simplest is to use range of two consecutive data points. This is called Moving Range of 2. For example, if you have an employee productivity data like following.

The moving range of 2 data points differences are shown in the above picture.

In case you are using range of more than two data points, then the minimum and maximum data point’s in the range are taken into calculation. For example if we have to calculate the moving range of 3 for the above data then our Moving range values will be like this.

The moving range of 3 took values 30, 28 and 27 and calculated the max (30) and min(27) values and their differences became the moving range values I.e. 3 for the data point.

In order to understand the Moving Range Chart we need to understand few terminologies which you will see in the chart.

Upper Control Limit: This is also called UCL. The UCL is the top or maximum limit set for the data point(s). If all the data points in a Moving range are below UCL, it is considered that the process or monitored item is under control.

To calculate the UCL following formula is used

Upper Control Limit = Average of data points + E * Average of moving range data points

Where E is constant which has a specific value. The value of E is calculated from the below chart. For example, If you are calculating the Moving Range of 2 then the value if E is 2.66.

Lower Control Limit: This is also called LCL. The LCL is the bottom or minimum limit set for the data point(s). If all the data points in a Moving range are above LCL, it is considered that the process or monitored item is under control.

To calculate the LCL following formula is used

Lower Control Limit = Average of data points - E * Average of moving range data points

Where E is constant which has a specific value.

If all the data points in a Moving range fall between UCL and LCL, it is considered that the process or monitored item is under control.

If there are data points in a Moving range which crosses the UCL or LCL boundaries, it is considered that that data points is an outlier and need to be investigated. We need to find out the root cause of what and why the data point is an outlier; what needs to be done to fix this?

Average of Moving Range: The average is calculated for all the individual data points and for all the moving range data points. The below image will clear this; we have calculated the Average of all individual data points and average of all moving range data points.

Once you have the UCL, LCL, Moving Range, Average calculated; you can lay down the Moving Range Chart. The MR charts of above data are following:

As you can see all the data points falls within the UCL and LCL; so we can conclude that the observed item(employee productivity) is under control. In case there are outlier we can review to find out the cause and come up with the resolutions we need to take.

I hope you like the article. Please let me know your opinion via comments.

Related Article:

• Project Quality Management: What is Quality?
• What is XMR Chart?
• Do you care for your Communication Style?
• Do you care for your Visual Communication Style?
• Do you care for your Kinesthetic Communication Style?
• How to improve your V.O.I.C.E?
• PM: How accurate is your Project Cost Estimates?
• PM: Do you know your Project Cost?