Lean Techniques for Process Optimisation
Six Sigma projects add value to business processes and generate value for customers. In each stage of a Six Sigma project, the objective is to reduce process defects. Processes are the driving force in Six Sigma projects. Along with processes, comes into the picture the concept of value addition and defects. A defect, in simple terms, means a deviation from specified requirements. Hence, any entity which is in non-conformance with processes results in defects.
Since a Six Sigma project aims to reduce defects, processes must be continuously optimized to produce a lesser number of defects at different stages of project execution. Therefore, the concept of lean techniques is used for optimizing the flow of value generation.
Table of Content
- 1 Lean Techniques for Process Optimisation
- 2 Mechanisms of Lean Techniques for Optimisation Flow
An example of value flow is the people who wait in a queue to be serviced at a restaurant or a service utility such as Metro Rail. In these examples, optimizing value flow means finding ways to bring value addition for the people standing in a queue or waiting at restaurant tables to be served a meal that is to be delivered via a queue-based system.
In these cases, processes that are not adding any value for customers require a relook. For example, the customer may be served light snacks and is waiting for the main course meal. This process of serving light snacks may be lean as it is not adding value for the customer, as he may be consuming food (snacks) that he has not ordered or the cost of serving snacks turns out to be too high in terms of the long waiting or serving time for the main course food.
The process of optimizing flow aims at preventing and eliminating stoppages and unnecessary wastages from the value chain. The process to provide a product or service to a customer begins to flow once the customer places an order and ends when the customer receives his complete order.
During the intermediary stages, value additions are taken into consideration and the requirements stated by the customer are addressed in as specific a manner as possible. This shifts the focus to the process of reducing defects.
Mechanisms of Lean Techniques for Optimisation Flow
Some mechanisms which are adopted for optimizing flow are as follows:
- 5S Tool
- Constraint Management
- Level Loading Mechanism Implementation
- Pull System Mechanism
- Implementation of Flexible Processes
- Reducing the Lot Size Mechanism
This is the most important tool which is deployed to eliminate process wastage. The 5S stands for:
Sort: This technique deals with the process of ensuring that only what is necessary is being executed. In other words, this means eliminating unnecessary steps in a process.
Set in Order
This technique involves ensuring that things that are required during the process execution are placed earlier in order so that they can be retrieved easily. Medical stores serve as a good example of the use of this technique. Medical stores keep in front those medicines that are commonly demanded. Also, they are put in sorted order.
This technique is designed to optimize the value-addition process. In essence, this technique involves maintaining neatness and cleanliness at the workplace to improve efficiency. Clean working conditions aid in the improvement of productivity by removing the clutter from the workplace.
This involves the process of determining, implementing, and maintaining a clean environment that works. In other words, a process may have a clean environment but if it does not work then it will not add value to the process.
This involves the formulation of habits that ensure that the workplace remains neat, tidy, and clean to improve the efficiency and productivity of the processes and the workforce.
A constraint is a limitation or a hindrance in the process execution phase. Every process operates under certain constraints. Also, every constraint consumes or requires some resources to remove the bottlenecks which arise from the constraint. Thus, constraint management itself becomes an activity that needs to be accounted for. The following are the points of consideration for constraint management:
- Each constraint must have the necessary resources to keep running.
- Every unit or resource provided to the constraint is of acceptable quality level.
- Every unit or resource produced by the constraint is of acceptable quality level.
- Constraint is operated in the most efficient manner possible.
Level Loading Mechanism Implementation
It involves a process of generating a stable, smooth schedule that is responsive to market dynamics. The goal of the level-loading mechanism is to make the same quantity of an item every day. In this way, process optimization is achieved to some extent. Level loading is done by using Takt time which is calculated as:
To create a level-loaded schedule, list part name, part number, daily quantity needed, and Takt time for each part. After this, sort the list by the quantity needed and Takt Time. This results in a level-loaded schedule.
Pull System Mechanism
In this type of production mechanism, items are produced when needed. The production process is required to deliver the product fast. This is in sharp contrast to the push system of production wherein the focus is to develop the product and then hope that the buyer may buy it.
Through the pull system mechanism, the producer can deliver the product as per customer requirements and thus able to eliminate the non–value addition activities in the supply chain management process. An example of the pull systems mechanism is the weekly vegetable market wherein the fresh stock of vegetables attracts buyers.
Implementation of Flexible Processes
Flexible processes involve the use of lightweight & maneuverable tools, and fixtures and equipment. They help in improving safety, quality, productivity, and ergonomics. Flexible processes can be compared to a hybrid combination of pull and level loading mechanisms. An example of flexible processes includes bakery shops which can quickly make any bakery items such as cakes as per customer requirements.
Reducing the Lot Size Mechanism
By reducing the lot size, the producer can control the excessive quantity produced by a process, which is not required by customers. In addition, larger lot sizes pose other problems such as feedback delays, excessive inventory, obsolete inventory, etc.