In the Continuous Lean Journey Mapping is the Starting Point
Hi dears, in our previous articles we covered the main definition of lean, what are the 8 wastes and how to eliminate them, then we went through the 5 main lean principles. After that, we started learning our magical lean tools starting with kanban, followed by continuous flow, takt time, pull system, heijunka, jidoka, JIT and how to implement each tool ?.
In today's article, we are going to continue learning our lean tools starting with one of the most important and familiar tool which is Value Stream Mapping (VSM). So after finishing this article you should be able to know what is VSM ? What are the VSM symbols ? What are the VSM terminologies ? What are the 4 elements of VSM ? and finally a step by step VSM creation. And Remember!! lean machine in the making.
Value Stream Mapping:
A value stream map (VSM) is a flowchart that illustrates and analyzes the steps involved in producing a product or delivering a service. Once someone maps the current state of the process from beginning to end, he or she should find areas that do not add value to the process and reduce those areas.
Symbols:
VSM symbols can be found in many places. However, they all fall under the following four categories: material, process, information, and general.
Terminologies:
Bottleneck: The operation or function with the lowest capacity, usually the operation with the longest cycle time per unit. The bottle neck sets the limit for the production pace and thus the capacity of the entire process.
Changeover: Activities that are required to prepare an operation or process for another type of product. The time allocated for this is called changeover time. Also known as setup time.
Cycle time: The time required to complete one cycle of an operation; or to complete a function, job, or task from start to finish. For automated or compound processes, the cycle time is the time between each output from the process.
Leadtime: Number of minutes, hours, or days that must be allowed for the completion of an operation or process, or must elapse before a desired action takes place.
Process time: Total time required to properly handle an item within a process step. This includes order preparation time, run time, move time, inspection time, and put-away time. For simple processes, the cycle time and the process time can be used interchangeably. See value-adding time.
Takt time: Frequency or pace of production required to meet customer demand. Defined as available time divided by customer demand. Sometimes the term customer takt time is used to mark the difference from the production pace (production takt time).
Downstream: Parts of the production process or value stream (or operations) that occur after an arbitrary point or operation. See upstream.
Upstream: Operations in earlier parts of the production process or value stream. See downstream.
Features:
Product flow: The product flow illustrates how the material moves through the process. How does the finished product, whether it is purchased components or raw material, become a finished product that can be sold to customers?
Information flow: Information flows govern the product flow. This document explains how the process is managed.
Customers: Customers are the first thing you should draw on your value stream map, start value stream maps in the shipping area, and move upstream. Include a data box that shows the customer's demands in addition to the customer symbol drawn on the map.
Suppliers: Next, draw the suppliers. You don't have to include every supplier on the map. Sometimes, it's more efficient to include just one type of supplier.
OK, let's learn how to create a current state value stream map in 10 simple steps:
Step 1 – Understand Value: Once we understand and define value for the organization and we understand the focus, we now start to develop the VSM.
Step 2 – What is our Focus?: To define our focus, we can use a tool like a Product Family Matrix to help us understand which of the products or family of products has the "biggest bang for the buck".
Step 3 – Go to Gemba (Walk the Process): Go to Gemba! Draw the Ohno Circle! Get a notepad, take notes and watch the process unfold in front of you.
Step 4 – Work Backwards: Start from the end of the process and work backwards, when you start from the end customer and work backwards, you have no choice but to track that "one thing", to avoid getting distracted by different paths.
Step 5 – Define the Basic Value Stream: From the data that we have collected from "going to gemba" and SME's, we define the basic steps in the value stream
Step 6 – Fill in Queue Times: After we define the basic steps in the value stream then we fill in Waiting (Queue) Times between each process.
Step 7 – Fill in Process Data: Enter all pertinent process data in Boxes beneath each main process step box (from step #5).
Examples of Process Data: Process Cycle Time, Changeover, Pace/ TAKT Time / Rate, Defects / Problems Per Day, First Pass Yield, Batch Size, Shifts.
Step 8 – Include Number of Labors: It is important to understand the amount of capacity in labor at each process. When developing the VSM, you might see that a bottleneck exists because of an imbalance in labor.
Step 9 – Include the Value-Added Percentage (%VA): Add up all the data in the VA section and divide it by the total process cycle time (the time it takes for the product or product family to travel through the entire value stream).
Step 10 – Interpret the Value Stream Map (VSM): The VSM should now be a very pictorial view of the process and what has happened to that product or family of products.
Bottlenecks / Constraints, Long Process Cycle Times, Poor Uptimes, Excessive Setup Times, Poor Quality / Rework.
The VSM should help build a roadmap for continuous improvement projects to get your process to the desired state.
To put it briefly, at the end of our article value stream mapping is an important element of lean operations, the goals of which are to maximize customer satisfaction and minimize waste. Operating in this way allows companies to do more with less, offering better value and higher quality to their customers. This requires utilizing project management tools to identify inefficiencies in the entire value chain, and that's where value stream mapping comes in.
Please feel free to drop me a line in the comments and tell me what you think of this article and if you have specific recommendations for a topic to be discussed later, also please contact me anytime for more clarification.
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Source: https://www.linkedin.com/pulse/lean-management-part-4-value-stream-mapping-journey-malek-gamil?trk=pulse-article