What is a time value map and how is it used in Six Sigma?

A Time Value Map is a tool used in Lean and Six Sigma methodology.It tracks a work item through its process and tracks where it spends its time.It follows the product from raw material to output into the customer's hands to determine where it spends valuable time and where waste time can be eliminated.To better understand what this means, we must first explore both Lean and Six Sigma a little.

Six Sigma methodology is a process improvement methodology using data and statistical analysis to identify and fix problem/opportunity areas for any particular company.A problem or process is identified, and defined objectively.The process's output performance is measured.The problem is analyzed in all phases of the process in order to identify causes of variation.By doing so, output processes can be improved by reducing that variation.This improvement program can affect everyone involved in all processes from production/manufacturing processes to service processes to business processes.

Lean is very similar.The difference is this: it is Lean when you need to attack waste, delay, over-production, large inventory, movement issues, waiting time, etc.It is Six Sigma when you are dealing with minimizing defects.

The reason Time Value Maps are so important in Lean and Six Sigma processes is because in order to reduce waste and variation to achieve a high quality production system, you will need to know where products are spending value adding and non-value adding (waste) time.If the idea is to identify where production can be improved, it only makes sense that you would want to find out where improvements can be made.

The concept of a Time Value Map is simple.You can track any work item into one of three categories.This you can map out with pencil and paper to analyze later on.Only work that is seen as Value added by the customer is plotted above the middle line, everything else is considered waste.A time line is then drawn up and the time segments are marked off for each category. The idle queuing time is represented by the blank space.

The first of these categories is Value added work.To better understand this term, you will need to consider the customer's point of view at the output stage.The customer sees the product and attaches value to it. They don't necessarily see what work went in to the production of that product, but the sum of that work is what created the product and either added value or didn't.The value the customer sees is what will provide an income for your organization, pay your salaries, pay for your building, tools and electricity.You are going to want to minimize any work going into the product that is not adding value from the customer's standpoint.So, the work that adds value to the product is called value-added work.

The second category into which you can track a work item is waste that is unavoidable due to business reasons.This can better be defined as the work or functions for which the customer does not pay for.This would include such things as payroll, legal services and regulatory or systemic expenses.

The third category is waste and delays.This could be long approval times before work can be completed or it could be handoffs back and forth between groups or people.

In summary, Time Value Maps are very important in Lean and Six Sigma processes.This is because in order to achieve a high quality production system, you will need to reduce waste and variation.To accomplish this, you will need to utilize Time Value Maps to identify where products are spending value adding and non-value adding time.