Value stream mapping is a lean enterprise technique used to analyze and improve the flow of information/material through series of value-adding events taking product/services from supplier to the customer
Value stream map (VSM) gives a visual depiction of the end to end process flow. Unlike standard process flow, VSM will not only have all process step in sequential order of production but also will show material and information flow and multiple data points like cycle time, waiting time, defect rate at each stage, inventory at each stage will also be depicted. It will be the one-page Bible for the leaders to identify improvement areas, recommend solutions and analyze the impact of a solution on other departments as well.
The primary objective of Value stream map is to identify waste and improve material/information flow. There is no standard way of how to use value stream map but at large most of the companies follow below mentioned general steps for creating value stream map:
- Define Scope
- As-is Value Stream Mapping
- Identify Value added and Non-Value Added activity
- Identify opportunities for Improvement
- To-be Value Stream Mapping
Here is the Value Stream Map cheat sheet for quick reference, it’s a one-page guide for preparing Value stream map. [Order my book “VALUE STREAM MAP – A Lean Tool For Process Improvement (All You Need To Know About)” on Amazon Kindle Store, available for Free till 9th March’2017, to learn VSM in detail)
|Step 1: Define Scope
The scope of VSM can be defined using two methods:
1. Fluctuation in Key performance indicator
2. Product Family Matrix: Products following similar process steps forms one Product Family. Prioritize family basis critical to customer or critical to business
|Step 2: As-is Value Steam Mapping
1. Build the map skeleton by drawing customer, supplier, process steps, and production control.
2. Add continuous material/information flow
3. Update current performance
|Step 3: Identify Value Added and Non-Value Added Activities
Value: Anything for which customer is willing to pay
NVA: Process step which is not adding value. The objective is to minimize essential non-value added time as much as possible.
Eight types of wastes can be identified in process: Transport(movement of material/product), Inventory, Motion (movement of people), Waiting (people/material waiting in queue), Overproduction (producing more than or before required), Over-processing (processing more than required), Defect (products not matching customer expectations)
|Step 4: Identify improvement opportunities
Kaizen is the practice of continuous improvement. The improvement opportunities are depicted in VSM as Kaizen-burst. Examples of improvement opportunities are Non-Value Added activities / Waste, high change over time/ cycle time, multiple/unnecessary communication, duplicate activities etc
|Step 5: To be Value Stream Mapping
Multiple Lean tools can be used to recommend improvement opportunities:
1. 5S = Sort, Set in Order, Shine, Standardize, Sustain
2. Standard work = Documenting most efficient way for doing work
3. Jidoka = Automation that will stop as soon as error occur
4. Visual Andon = Visual signal that shows the status of a process.
5. Poka Yoke = Mistake proofing to prevent or detect errors
6. Kanban = Signal cards used to denote product details
To-be Value stream mapping should be drawn assuming all recommendations are implemented. An implementation plan should be finalizes