Lean Manufacturing As A System
Enviado por llfh • 3 de Octubre de 2011 • 4.177 Palabras (17 Páginas) • 1.506 Visitas
Lean means "manufacturing without waste." Waste ("muda" in Japanese) has many forms. Material, time, idle equipment, and inventory are examples. Most companies waste 70%-90% of their available resources. Even the best Lean Manufacturers probably waste 30%.
Lean Manufacturing As A System
Lean Manufacturing explained from a "Systems Thinking" perspective
Lean Resources
China
Lean Manufacturing Academy
Europe
Jung, Aust & Partner
Australia
Peter J. Ellis
North America
Sims Consulting Group
Strategic Impact
Lean Manufacturing systems have interrelated elements that form a system or Manufacturing Strategy. The graphic shows how these elements work together and reinforce each other. Each arrow indicates a positive influence or relationship. For example, Fast Setups enable small batches, and small batches result in smoother material flows. Note the number of circular loops. Such loops continuously reinforce each other driving the system to higher and higher levels of performance�like a snowball rolling downhill.
These effects are part of a body of knowledge known as "System Dynamics", "Industrial Dynamics", or just "Systems Theory". A factory system has both technical and human elements which immensely complicates theoretical analysis. Moreover, such systems may exhibit very strange behavior such as instability and chaos. Lean Manufacturing addresses many of the elements that reduce chaotic effects such as variability, time delays and complexity.
It is difficult to study such systems directly since their complexity makes modeling difficult. Our understanding generally comes from working with simpler models and extrapolating the results through intuition and general principles. For a complete discussion of these systems and related phenomena, go to "Principia Cybernetica Web".
Lean Manufacturing and Cellular Manufacturing improve material handling, inventory, quality, scheduling, personnel and customer satisfaction. For examples and hard numbers on these improvements see Benefits. The payoff to shareholders is significant and documented. A history of these developments is at "A Brief History of (Just In) Time."
Core Disciplines
Most waste is invisible. Nor is elimination easy. A set of techniques that identify and eliminate waste has evolved: "Lean Manufacturing."
►Cellular Manufacturing
►Pull Scheduling (Kanban)
►Six Sigma/Total Quality Management
►Rapid Setup
►Team Development
These are core disciplines. Not every organization requires them all. Others require supplementary disciplines. Determining which disciplines are most important and/or urgent is the subject of our Lean Implementation series. You may also find our series on Leadership useful.
Tools
Value Stream Mapping and Process Mapping are two valuable tools that can help eliminate waste and streamline work. Group Technology can sort out workflow in complex product mixes. Other analysis tools are also available.
Inventory
Besides core disciplines and tools, there is an overall theme of inventory reduction. Inventory hides waste. Almost every imperfection or problem creates a need for inventory. Hence, inventory is a result and measures the imperfection of the system.
People & Technology
Factories include people. To function well, people and technology must integrate in a system exploiting the strengths and minimizing the limitations of each component. Every core discipline has a psychological component. Eric Trist called this a Socio-Technical System.
The Systems Perspective
The core disciplines are interdependent. Each acts upon and improves the others in a continuous "Virtuous Circle". Over time, this reinforcement builds momentum like a snowball rolling downhill. Results for the system are greater than the separate effects. For more, see "Manufacturing As A System."
Science Vs. Slogans
Strategos prefers a scientific and engineering perspective rather than slogans, edicts, imitation and proselytizing. Science necessarily includes the human disciplines since all factories are Socio-Technical Systems.
This allows us to carry principles into new and different industries where there are no examples to copy. See our page on Factory Science.
"...the tools and artifacts were developed to deal with very particular problems that were affecting people in very particular circumstances. Working under different circumstances presents different problems, which requires different tools and different thinking." So says Steven Spear of Harvard who wrote "Decoding The DNA of the Toyota Production System."
Using This Site
You will find useful information and tools here. The "Resources" section has various Lean Manufacturing articles, information and perspectives. For example, the "Assessment" helps determine your current position.
The "Seminars" section details training programs and Kaizen Events. It can assist you in grasping the body of required knowledge. You might also want to visit the page on "Developing Your Training Plan. The "Site Guide" lists types of resources. "About Strategos" outlines our approach and tells you about the Strategos team.
Download expanded & Printer-Friendly Version of This Page in PDF.
Workcells In Lean Manufacturing
Cellular Manufacturing and workcells are at the heart of Lean Manufacturing. Their benefits are many and varied. They increase productivity and quality. Cells simplify material flow, management and even accounting systems.
Cellular Manufacturing seems simple. But beneath this deceptive simplicity are sophisticated Socio-Technical Systems. Proper functioning depends on subtle interactions of people and equipment. Each element must fit with the others in a smoothly functioning, self-regulating and self-improving operation.
What Is A Workcell?
A workcell is a work unit larger than an individual machine or workstation but smaller than the usual department. Typically, it has 3-12 people and 5-15 workstations in a compact arrangement.
An ideal cell manufactures a narrow range of highly similar products. Such an ideal cell is self-contained with all necessary equipment and resources.
Cellular layouts organize departments around a product or a narrow range of similar products. Materials sit in an initial queue when they enter the department.
Once processing begins,
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