Tally Chart:: Continuous Process Improvement

“In god we trust, All others bring data” is a saying that is attributed to the Quality Guru W.E. Deming, the meaning being that if we really want to know what is going on we had best get off of our seats and go get some hard facts and figures using tools such as tally charts for continuous process improvement. One of the simplest tools for doing so is the simple tally sheet, something that most of us will be familiar with from school let alone in business! This tool is far too often forgotten but it’s power to collect data quickly simply and efficiently should not be overlooked.

A tally chart is probably the simplest and oldest way to record data, it is merely a table of how often a specific occurrence happens, normally put together when the event occurs. I am sure that as a child you may have sat beside the road with your teacher with a tally chart and put a mark to show every time a red, blue, silver or white car went past you, I am not sure if in these days of health and safety if these trips still occur.

It’s use in business is as simple as this, it can be used to record defects against categories as a machine works, the number of requests made of a department each hour and so on. As one of the basic quality tools a tally chart feeds into many of the other tools to help you achieve continuous process improvement.

A tally chart should be as simple to use as possible, you should not have more than around 10 categories against which to make your tally mark, more than this and you run the risk of mistakes and wasting time trying to find the correct box to tick, I have seen far to many data collection sheets on factory floors with 30 or 40 reject causes and sub causes that the operator has to decipher, usually resulting in “other” being the main cause of rejects as the operator cannot be bothered to find the right box.

You can use pareto analysis to identify the top categories for your tally chart to use, this is a very simple tool to identify the vital few areas the cause the majority of the problems.

When using a tally chart ensure that you use relevant data and that the people recording the data understand what you are looking for.

An example is a bottling plant that I once visited and did some work for as a consultant, they collected reams of data on the shop floor and their tally charts showed that over 90% of their downtime and rejects were caused by incorrect bottles. They identified the causes as being bottles that were of the wrong shapes and dimensions, thousands were rejected every day!

The result of this was a very sour relationship between the supplier and the company, a lot of time being spent on investigating the dimensions of the bottles. Re-dimensioning of drawings as people could interpret them in different ways. Even the commissioning of new tools to try to alleviate the problems.

But was this data correct? Were the operators recording what the engineers and management actually wanted them to record and did those engineers and managers themselves understand what they were looking for?

The answer of course is no, instead of recording what actually went wrong on the line, such as a bottle falling over and causing line jams or a cap not being fitted the operators assumed that the problem was down to an incorrect bottle!

One day spent on the line collecting the real issues not supposed causes gave some real data that could be looked at, combined with actually observing the process with a critical eye resulted in all of these problems vanishing within 48 hours and the “reject” bottles all being able to be processed on the line!

Years of arguing and heartache caused by not recording relevant data and people failing to understand and question the data!

Analysis itself is relatively simple, you can analyze your data in the same manner as a Pareto chart or simple histogram (Bar Chart), displaying the data as a visual chart is far more effective than just a table of numbers.

The data from your tally chart once organized as a histogram (bar chart) or a Pareto chart can then be used to direct your efforts to resolve problems and improve your business performance. After all what we are aiming for here is continuous process improvement, not just gathering data. Now we need to find a solution to the top issues as indicated within your analysis.

Techniques such as Brainstorming, Fishbone Analysis and the 5 whys are all powerful tools that can help you focus on the issues highlighted by your data collection. Starting with the highest problem on your analysis you can work your way through the causes continually improving your processes.

For Continuous process improvement to happen, it has to be planned and managed. Without this continual process of business improvement you will always be chasing your competitors and your problems. If your business is to flourish then there are a number of tools that you can utilize to help you drive continuous process improvement, Tally Charts are one tool, some of the other quality tools that you could use are;

PDCA, Plan, Do, Check, Act, a technique to help you plan your improvement activities

Pareto Charts, use the 80:20 Rule to Identify the vital few areas to tackle.

Histograms or Bar Charts, to graphically represent your data to make easy visual analysis.

Brainstorming and Mind Mapping, to generate ideas and organize them.

Fishbone Diagram or Ishikawa Diagram to show cause and effect in a simple manner

Process mapping, to highlight all of the wasteful steps in a process, also Value stream mapping to highlight the waste in the whole business.

Statistical Process Control (SPC) Charts, to measure and monitor the process output and parameters.

The 5 Whys, to help drive you to the true root cause of a problem.

The following links will help you with regard to understanding and implementing quality tools and continuous quality and process improvement;

Chartered Quality Institute (CQI) The Chartered Quality Institute

American Society for Quality (ASQ) American society for quality

Lloyds Register Quality Assurance (LRQA) Lloyds Register Quality Assurance

British Standards Institute British Standards Institute

American Standards Organization American Standards Organization

Quality Institute of America Quality Institute of America

Quality Institute in Healthcare Quality Institute for Healthcare

Institute for Manufacturing (IFM) Institute for Manufacturing

These links will help you with finding out about tally charts and other quality tools for continuous process improvement.