Lean Manufacturing is the systematic elimination of waste, and the implementation of continuous flow concepts and customer pull. Lean is the best management system for satisfying customers on delivery, quality, and price.

Many companies are turning to lean manufacturing in an effort to become more profitable. Implementing "Lean" can create superior financial and operational results. Lean manufacturing comes from the Toyota Production System. Practiced by Toyota for many years the ultimate goal of the syste, is to produce quality products by cost reduction activities and a cultural focus on employee involvement through empowerment. Lean manufacturing uses concepts pioneered by Toyota Motor Company’s former vice president Taiichi Ohno. This "new" manufacturing culture is based on working in every facet of the value stream, to include instilling the discipline to reduce cost, to generate capital, to make the money, to bring in more sales, and to remain competitive in a growing global market.  

Lean Manufacturing

The Value Stream of a business is the sequence of steps that a company performs in order to satisfy a customer’s need. In every Value Stream, a 50-70% reduction in the number of steps in the process can be achieved. The first step a company must take to change their value stream is to determine its lean status by identifying efficiency gaps and areas for waste/cost reductions. Lean manufacturing is a fundamental enterprise transformation that must be approached as a total organizational and cultural transformation. Value stream mapping is a good way to train staff to find waste, identify the root cause, and prepare a strategic plan for its elimination.

The seven categories of non-value added waste are overproduction, inventory, transportation, waiting, motion, over-processing, and correction. Overproduction is a source of waste for most firms and is referred to as the batch and queue mode of operation. This large-batch processing mode is an outdated paradigm. Another problem with large batches is that there is no connection between the pace of production and the pace of demand. Reduced lot sizes with quick set-up capability is the paradigm of the 21st century. Producing various models in small lots improves responsiveness to customers and flexibility to respond to changes in demand. The smaller the lot means the smoother the process flow. The following five areas drive lean manufacturing/production: cost, quality, delivery, safety, and morale. Lean manufacturing views continuous, one-piece flow as the ideal and emphasizes optimizing and integrating systems of machines, materials, people, and facilities. Continuous flow follows the produce one-by-one as efficiently as possible ideology.

Lean manufacturing elements

Waste elimination, continuous one-piece workflow, and customer pull are the basic elements of lean manufacturing. Focusing these elements in the areas of cost, quality, and delivery forms the basis for a lean production system. Lean techniques can also be applied to the service industry. In the service industry eliminating waste is the process of eliminating anything that does not add value to your customer.

What is Lean

By definition, lean manufacturing is the systematic elimination of waste from all aspects of an organization's operations, where waste is viewed as any use or loss of resources that does not lead directly to creating the product or service a customer wants when they want it. In many industrial processes, such non-value added activity can comprise more than 90 percent of a factory's total activity1. (More information about the types of waste in lean manufacturing.) Lean manufacturing – also known as lean, agile manufacturing, or Just-in-Time production – was originally developed by the Toyota Motor Company in Japan based on concepts pioneered by Henry Ford.

Nationwide, numerous companies of varying size across multiple industry sectors, primarily in manufacturing and service sectors, are implementing lean production, and experts report that the rate of lean adoption is accelerating. Companies generally choose to engage in lean production to boost company profits and competitiveness. These efforts have three primary objectives:

• Reduce production resource requirements and costs;
• Increase customer responsiveness; and
• Improve product quality.

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How is Lean Manufacturing Different from Traditional Manufacturing?

Lean involves a fundamental paradigm shift from conventional "batch and queue" mass production to product-aligned "one-piece flow" pull production. Whereas "batch and queue" involves mass production of large lots of products in advance based on potential or predicted customer demands, a "one-piece flow" system rearranges production activities in a way that processing steps of different types are conducted immediately adjacent to each other in a continuous flow.

This shift requires highly controlled processes operated in a well maintained, ordered, and clean environment that incorporates principles of employee-involved, system-wide, continual improvement.

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Lean Methods

There are numerous methods that organizations use to implement lean production; the most commonly used methods are listed below. A summary of the environmental implications of each method is also available.

While most of these methods are interrelated and can occur concurrently, most organizations begin by implementing lean techniques in a particular production area or at a "pilot" facility, and then expand use of the methods over time. Companies typically tailor these methods to address their own unique needs and circumstances. In doing so, they may develop their own terminology around the various methods.

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Overall Lean Frameworks

Kaizen Rapid Process Improvement Events — Kaizen (Japanese for "to take apart and make good") refers to the continuous, incremental improvement of production activities. It is typically implemented through frequent, structured worker-oriented events that last 3-7 days.

Value Stream Mapping — A process mapping method used to document the current and future states of the information and material flows in a value stream from customer to supplier. Lean practitioners use value-stream maps to identify targets for future process improvement activities (e.g., kaizen events).

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Process Improvement Methods

5S — An improvement process involving five steps (Sort, Set in order, Shine, Standardize, and Sustain) to create and maintain a clean, neat, and orderly workplace. Some organizations add a sixth "S" for Safety.

Standard Work & Visual Controls — Standard work represents the best ("least-waste") way to perform a given operation. Visual controls are used to reinforce standardized procedures and to display the status of an activity so every employee can see it and take appropriate action.

Cellular Manufacturing — An approach where manufacturing work centers (cells) have the total capabilities needed to produce an item or group of similar items; contrasts to setting up work centers on the basis of similar equipment or capabilities, in which case items must move among multiple work centers before they are completed.

Just in Time (JIT) / Kanban — Just in time is a production scheduling concept that calls for any item needed at a production operation – whether raw material, finished product, or anything in between – to be produced and available precisely when needed. Kanban (signals) are used to control levels of inventory and work in process.

Total Productive Maintenance (TPM) — An approach to enlist operators in the design, selection, correction, and maintenance of equipment to ensure that every machine or process is always able to perform its required tasks without interrupting or slowing down defect free production.

Six Sigma — A methodology and collection of statistical tools to reduce variation and improve business processes. Six sigma aims at a defect rate of no more than 3.4 defects per million chances.

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Advanced Lean Enterprise Methods

Pre-Production Planning (3P) — The lean method for product and/or process design. 3P designs and implements production processes, tools, and equipment that support one-piece flow, are designed for ease of manufacturing, and achieve appropriate cost, quality, and lead time. Also known as Production Preparation Process.

Lean Enterprise Supplier Networks — A set of buyer-supplier relationships where organizations apply lean production concepts across the supply chain to reduce costs, delays, and other wastes.

Types of Waste Targeted by Lean Methods

Lean methods typically target eight types of waste. Each of these wastes has a potential environmental impact, shown below. It is interesting to note that the "wastes" typically targeted by environmental management agencies, such as non-product output and raw material wastes, are not explicitly included in the list of manufacturing wastes that lean practitioners routinely target.