MANUFACTURING SOFTWARE EXECUTIVE GUIDE  

AN EXECUTIVE'S GUIDE TO LEAN MANUFACTURING SOFTWARE

Lean Manufacturing
Lean manufacturing, also referred to as lean production, lean scheduling or just 'lean', is a production practice that targets the elimination of all input, process materials and by-products not directly associated with the end finished product. Lean manufacturing is a broad manufacturing process methodology originally created by Toyota when the company constructed its Toyota Production System (TPS) in the 1990s. Lean manufacturing gained global interest and notoriety as Toyota's implementation of these methods enabled the car company to grow from a small auto manufacturer to the world's largest automaker.

Enterprise Resource Planning (ERP) software applications have evolved to support lean manufacturing production methods and cost accounting (sometimes called project accounting or job costing) methods needed to categorize and measure both necessary and inefficient cost types. Today, marketing leading manufacturing software systems from SAP, Oracle, Infor, QAD and more provide specific workflow processes, feature sets and information reporting to support customers in their adoption or use of lean manufacturing.

Waste Categorized and Explained
The elimination of manufacturing waste is the primary goal of the lean methodology. Because waste is loosely defined and not always recognized, Toyota identified the three waste categories of muda (無駄), muri (無理) and mura (斑, ムラ). Muda is a term for wasteful, Muri is best translated as unreasonable and mura describes an unevenness or inconsistency. The Japanese prefix 'mu' for each of these terms is a reference to a product improvement program or campaign.

An illustration of the Japanese kaizen thinking includes the recognition that only the last turn of a bolt actually tightens it, while the rest of the motion is simply movement. This type of unconventional thought process is key in defining manufacturing waste and properly identifying the divisions between value-added activity, waste and non-value-added effort. Non-value added effort is production waste that is most often routinely and unquestionably performed. Most lean planning methods begin by measuring the magnitude of these wastes so that elimination of waste can be quantified, forecasted and objectively measured.

Muri is all the unreasonable work effort that supervisors impose on line workers and machines because of poor planning. For example, carrying heavy weights, moving things around and unsafe tasks are all examples of muri. Unreasonable work efforts are normally associated with multiple variations.

To link these three conceptual concepts is the basis of Lean. Muri addresses preparation and planning of processes, particularly identifying what work efforts can be proactively avoided by thoughtful design. Then mura addresses how the work design is implemented and how the fluctuation at the scheduling or operations level is eliminated. Muda is then identified after the production process is in place and is responded to reactively. It is management's role to examine the muda, in the production processes, and eliminate the root causes by linking the connections between the muri and mura of the systemic process. The muda and mura inconsistencies are then relayed back to the muri, or planning stage for the next run.

A common business scenario demonstrating waste and the relationships among muda, muri and mura is the business behavior of adjusting period-end production in order to achieve previously forecasted figures. As the end of a fiscal period approaches, production demand is increased in order to 'make the numbers', thereby increasing (mura). When the numbers are artificially increased production is forced to to try to squeeze extra capacity from processes which causes manufacturing routines and standards to be stretched. This stretch and improvisation leads to muri-style waste inefficiencies which then leads to machine or system downtime, errors and standby idle time, thereby triggering the muda of waiting, correction and additional movement.

The lean 'Flow' based method strives to incorporate JIT (Just In Time) inventory management and reduce the variation caused by variable work schedules and ultimately deliver a driver for improved inventory stocking on conjunction with other lean principles. However, JIT inclusion also exposes many quality problems that are hidden by safety stocks and less than optimal EOQ (economic order quantity) methods. While challenges, these issues can be dealt with if a lean project's scope can be slightly enhanced.

While muda vary by corporate entity, the original seven muda included the following:

Transportation and movement (shifting products that are not actually required to perform the processing)
Inventory management (all items, WIP and finished products not being processed)
Motion (people or equipment moving more than is necessary to perform process requirements)
Waiting (remaining idle between production steps)
Overproduction (production beyond demand)
Over Processing (excessive setup or similar activity due to poor tool or product design)
Defects (the work effort involved in inspecting, identifying and resolving product defects)

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