Lean Six Sigma Manufacturing

Trying to give what I believe to be the best  answer to the question “What is Lean?” I would propose the following definition, initially expressed  by Womack in 1990 :


“Lean is a production philosophy that focuses on the streamlining of value added activities and eliminating waste within the process with the goal to better meet customer demand.”


This quotation contains key factors of lean manufacturing systems.  I would like to try and illustrate in a simple way these factors.




Value stream mapping is the first and probably the most important lean tool to be used in improvement projects. The steps that need to be followed when approaching this method are:






The fourth step which I’ve highlighted, often is not applied and the typical answer  given to such step is: “We already know where the problems are!”  However, when a consultant is called to take part in such improvement project  and presents the activities that need to be done, starting with the 5S, the first thought that comes to mind is that “It’s not  what we are looking for.” (what we had in mind)


 Skipping this step means losing an effective opportunity to understand the process and being penalized to a less efficient result.


Value stream mapping is the best way to identify where the most significant improvement opportunities are.


This technique  allows you to envision all the activities required in the complete realization of a product   -going from the supplier to the customers -  Through a graphic representation in which  you can visualize the the value added or the sources of waste present in such processes.



I  would like to exemplify the differences between value added and non value added activities:


Value added activities include  all the work or services that the customer is willing to pay for.

Non value added activities  are the actions that do not contribute to the product or service and should be eliminated.

Among the all the activities  we can also find Non value added but necessary activities which do not contribute to the product or the process, but are necessary to keep the value added work going.




The objective is to reduce waste and at the same time be able to reduce costs and time.










A guide line to apply VSM can be:


  1. Getting started / Selecting a Product Family
  2. Current state-map
  3. Future state-map
  4. Work plan


Current State Map is the mapping of the flow of material and information drawn using a serious of symbols and graphics to identify the Lead Time of production, which is the time needed for the work piece to go from the manufacturer to the customer, the process from the start to the end. This process can be done with the help of all of those who come into contact with such stream. A current state map also allows you to establish the different connections between the customer areas, the suppliers, the actual manufacturing processes and the entire business system. However, such map can be created through the acquiring of different factors such as process times, inventory or materials information and customer demand. Also with the collaboration of the entire team with whom we can identify waste or value.


Future State Map is a further analysis of the current state map, in which we try and distinguish the imperfections in value stream mapping, trying to change the parameters in order to optimize the entire process. Examples of such parameters are:

  1. Time
  2. Quantity of stock
  3. Tackt time


Once this process has been done, we can create a further map with less defects in comparison to the first. The aim of such process is to meet in the best way possible, the needs of the customer in a faster, more efficient way without however, affecting the company itself. It needs to bring advantage to both and only through such process we can obtain value. Lean thinkers retain that even the single person that comes into contact with such stream, must participate and work in partnership with others to improve the value stream.


The guide lines that are necessary to maximize productivity and minimize lead time are :









I would like to propose an interview between a lean thinker and a company, trying to understand the motivations that bring a company in using these tools


LT: Lean thinker

C: Company


LT: Why did you choose VSM as a tool?

C: It is a tool which improves communication and allows a common view of the problem. It gives you knowledge on other processes , giving useful information about them.


LT: What is the scope of such tool?

C: The scope of such tool is to break down complex processes into smaller process in order to facilitate the analysis.


LT: Who could lead such process?

C: We assign the responsibility of this process to a change agent or an expert of such department that has a already a certain level of knowledge of lean tools.


LT: Who could provide support?

C: A team dedicated that support s the activities is essential to reach success .


LT: What is the knowledge needed to face the project?

C: It’s important to have a brief introduction of the methodology to prepare the members of the teams in order for them to start thinking lean.


LT: What is the procedure adopted?

C: From the beginning to the end.


LT: How is the data collected?

C: Initially, we organized meetings where every member expresses their opinion. Applying the right methods allows us to obtain accurate data.


LT: Is there a future map drawing in the guideline?

C: Yes.