Thinking of Lean Manufacturing Systems
By Akin O. Akinlawon, Managing Director, Manufacturing Solutions/ Industrial Automation Group, Comdisco Inc.
The importance of Lean Manufacturing System is better comprehended when its impact of change on economics is thoroughly understood. The manufacturing engineering philosophy is pivoted on designing a manufacturing system that perfectly blends together the fundamentals of minimizing cost and maximizing profit. These fundamentals are Man (Labor), Material and Machines (Equipment) - called the 3Ms of manufacturing. A well balanced 3M results in
There are three steps involved to accomplish the ultimate manufacturing engineering philosophy:
Alternative concepts may be generated that could satisfy product and marketing technical requirements based on thorough review or re-examination of intra- and/or inter- technologies, past production process errors and lessons learned, competitive analysis, techno-communication as may be applicable. The final selection of manufacturing system concept(s) to be adopted for further consideration or development should be based upon analysis performed in conformance with established selection criteria. Let us consider two manufacturing systems that when combined give Lean Manufacturing - Flow Manufacturing System and Agile Manufacturing System.
Design Simple Manufacturing System
Flow manufacturing is a time-based process that pulls material through a production system without any interruption. This is a fundamental principle of Lean Manufacturing. This process concept can be achieved by--rapidly flowing material from raw to finished good--systematically balancing man (operator) and machine (equipment) to customer requirement.
The goal of Flow Manufacturing is to provide the ultimate response and produce to customer requirement. The benefits of this goal include:
In Flow Manufacturing, the performance is measured by the Total Product Cycle Time (or Critical Path). Total Product Cycle Time is the longest lead time path from raw materials to finished goods. This is the quickest possible response to a customer order with finished product. Lead Time Analysis is derived from the Critical Path which enables us to highlight opportunities to reduce or eliminate NVA activities and thereby shorten the Total Cycle Product Time. By reducing the variations in the rate of flow in a manufacturing system, the lead time may be shortened. The variations can be reduce with
Agile Manufacturing is a profitable manufacturing system that is closely related to the concept of Flow Manufacturing. It builds on the Flow Manufacturing concept to reduce lead time, optimize asset utilization and build to customer demand by focusing on being able to quickly respond to customer requests. It assumes that the customer requirement (specifications and volumes) is subject to continuous changes. A form of measurement of Agile Manufacturing performance is the program lead time.
Realize There is Always Room for Improvements
The ultimate goal is a system that has a smooth flow of material while maximizing the value added (VA) activities of the operator. Usually there are many situations in System Design Process that require special consideration. A few of these situations include:
Total Product Cycle Time (also known as Critical Path) is the longest lead time path from raw material(s) to finished goods. This is the quickest possible response to a customer order with a finished product. NVA activities in manufacturing system is waste. These wastes are correction, over production, movement of material, motion, waiting, inventory, and processing. Improving the flow of material through improved system layout at the customer's required rate (takt time) would reduce waste in material movement, inventory (work in progress) and improve the ability to be a JIT manufacturer. Therefore it is essential to properly apply the methodology of Lean, Flexible, Customer Focused Cellular Layout, Material Flow and Transfer, Takt Time and Operator Utilization in order to achieve the goal of Flow manufacturing and JIT.
Continuously Improve the Lean Manufacturing System Design
To be able to quickly respond to customer requirements and be a JIT manufacturer concurrently, one of the keys is to have the flexibility of equipment and have the ability to align it with product flexibility. Due to the uncertainty in customer requirement, it is important to examine manufacturing cost over a range of volumes.
Traditionally, there is a steep drop in manufacturing cost as the ideal volume requirement is approached and a steep rise as the volume is in excess of requirement. This system is generally characterized by:
However, in Lean Manufacturing, the manufacturing cost does not have such a steep drop as volume requirement changes. This is because of the product flexibility and equipment flexibility that can be incorporated into the Lean Manufacturing System. This system is usually characterized by:
Lean Manufacturing System has potential for greater profit (higher RONA). The profitability depends on the utilization of its resources - the 3Ms viz
Lean Manufacturing System can be adopted in new manufacturing system, existing manufacturing system requiring capitalization, equipment or product relocation.
Mr. Akinlawon can be reached at firstname.lastname@example.org.