Lean Manufacturing

This document describes our personal view of the meaning, principles and some of the problems of Lean Manufacturing and what it should encapsulate. It encompasses the works of Feigenbaum, Deming, Juran, Shingo, Taguchi, Ishikawa, Imai, Peters and of course our own experience. It encapsulates the elimination of waste, quality planning and control (not TQM), Just in Time, supplier integration, automation, team working, empowerment, behaviour, preventive maintenance (TPM), delivery frequency, selling techniques, new product introduction, and agile manufacturing.

Links to other best practices and training at bottom of page

Based originally on the Toyota Production System (TPS), "lean" manufacturing explained by Womack Jones and Roos, Imai, and others, provides a radically different way of running manufacturing. However we feel that some important aspects particularly behavioural aspects make it incomplete. We would define a truly lean philosophy as including:

• Elimination of Waste (Continuous improvement). A point often forgotten in waste reduction is that waste can only be defined and certainly only prioritised in the context of understanding the purpose of a process. A second major issue with "Total" quality is the mismanagement of the improvement process, which at worst can actually prevent improvement, and create cynicism towards the initiative. The principle of total quality is that everything is being improved all the time. This effort is often beyond the resources of the current staffing and management support capability at the outset of a continuous improvement programme. Also because everything is trying to be improved at once, problems can arise with priorities. Priority is in the eyes of the beholder and conflicts can arise. Because of this, highly focused improvement systems can be accomplished by ensuring that the priorities are clarified first, and that these are the graphs on the wall, before continuous improvement is started. (See Focused Improvement Systems and Previous Best practice of the Week 041: "21 Barriers to Lean And Agile") Also continuous improvement where the core is rotten often gives rise to dissatisfaction, necessitating a properly resourced major change programme first. (Also see Culture Development Methods & World Class Change Management, BPR, and Benchmarking)
• Total quality up to now, is most comprehensively defined by the combined works of Feigenbaum, Deming, Juran, Shingo, Taguchi, Ishikawa, Imai, and Peters, (any one of whom we view as having an incomplete picture) includes the following:

Culture. (See "Culture Development Methods & World Class Change Management")

• This requires leadership with a ruthless passion for perfection to create attitudes in all employees so that their behaviour positively influences product and service quality. It also requires the empowerment of all employees to sacrifice output and cost in the pursuit of quality and to own the problem. These principles have to be supported by policies, procedures & management behaviour, rather than slogans or banner exhortations. Unfortunately it is still common to see the ISO 9000, or QS9000 badge in the reception area of the company and indifference to quality on the shop floor. Also many companies who want the badge but do not operate the philosophy on the shop floor must disappoint the disciples of "Investors In People". Sustaining this culture is a significant challenge to any organisation, in the light of business and personnel changes. (See Focused Improvement Systems)
• Team working implies that there is a team, who are organised and behave like an empowered, engaged, self-directed, team, which we discuss in our OM01 "Organising & Engaging the Team" training course.
• It is assumed by all staff that poor quality is a major waste and must be improved to "near perfect",  by continuous improvement, with employees empowered to stop production to solve problems permanently by the use of simple problem solving tools such as the "5 why’s". (See: "6 Steps To Near-Perfect Quality")

Structure (See "Organisational Redesign")

• Low and high level ownership of quality
• Technical and management support to resolve problems
• Removal of indirect workers, broadening of narrow job classifications and cross training
• Keeping the responsibility with the originator, not the technical support functions
• Short feedback loops based on shallow organisation structures
• Mechanisms for continuous improvement with routine daily stand up team meetings to flush out problems. This may include "Quality Circles", but the provision of a facilitator to provide mentoring, on-going training and administration support is more common.

Systems. There are a huge range of techniques and systems (Many of which we include in our range of ongoing improvement workshops, which can:

• Prevent problems (Taguchi experiments, Design for manufacture, Quality Function Deployment, Pokayoke, Failure Modes and Effects Analysis, Housekeeping (5 S's), etc.). Ford’s Q1 quality system introduced in the 80’s, followed by ISO and QS standards have attempted to define an auditable process.
• Detect problems. (Statistical Process Control, Management By Walking Around, Customer satisfaction, surveys, Audits, Product strip down, and still prevalent is inspection and testing etc.)
• Analyse the root cause of problems. (Pareto analysis, measles charts, Ishikawa / fishbone diagrams, 5 Why’s, flow / time charts, value stream mapping, etc.). Kaizen events are also a way to focus development effort & the use of these tools on a particular problem.

(Many of these techniques are also covered in "Previous Techniques of the Week" available on request)

A more recent definition of quality management based on our latest research & our experience is discussed in more detail in "Six Steps to Near-Perfect Quality". Also more recently in our Business Process Reengineering training we define the "six drivers of performance" which we will cover in a future article.

• Just in Time (JIT) production (making only the quantity required, when it is required, as inexpensively as possible), and it's associated logistics management process "Kanban"
• Increasing delivery frequency
• Supplier integration. This starts with segmentation, supplier reduction, then progresses to category management, forming strategic partnerships, followed by integration which may or may not include shareholding, but certainly includes systems integration. Forms of systems integration include supplies collection rather than supplier delivery, supplier top up to point of use, warehousing, third party kitting, "tiering", and EDI. (See Lean Supply Chains)
• Appropriate use of automation (avoiding one of the 21 wastes).
• Preventative maintenance (TPM). Although the measurement of "mean time between failures" has been understood for decades, preventive maintenance has been slow to gain acceptance, as opposed to fix it when it goes wrong, except in the transport industry. This is barely acceptable for non-bottleneck processes but is totally unforgivable for bottleneck processes. Recent developments in this field include "Total Productive Maintenance", the main themes of which include continuous improvement, ownership and routine maintenance / servicing by the "owner". The maintenance function’s role is then elevated to include major work, prevention and training.
• Design for manufacture including standardisation of parts. We have recently expanded this definition to include the whole product life cycle, e.g. "design for servicing" (See 6 steps to near-perfect quality)
• The original concept also incorporated "aggressive selling" which would be better described as continuous selling rather than the sales-promotions approach of the West. (See "Demand Management"). A third way which is gathering momentum now is described by "Agile Manufacturing"
• Design project management rather than functional co-ordination incorporating the ideas of:

• Market led design. (See Previous Best practice of the Week 038: "Product Design Parameters")
• Concurrent engineering and team-working in the design process led by a project manager owning the design team for the duration of the design process and up to and including full production. (See New Product Introduction).
• Improved communication, partly bought about by team working, but also deliberately sought conflict at the early design stage, to bring to the surface the trade-off’s between function and manufacturability and a parallel (not serial) design process. This includes involving suppliers in the design process, and assembler involvement in the component design process. It also includes joint problem solving with the free movement of personnel and ideas between supplier and assembler. (See Previous Best Practice of the Week 036: Collaborative Engineering (or why concurrent engineering is only half of the story))

There are however dangers in the strict application of the techniques above to supply chains. Without agility (See Agile Manufacturing) leanness can lead to shortages. We have encountered several examples of this. However most of these examples are due to the faulty operation of the control systems rather than the features of the control system itself. The three biggest reasons for failure are that a Lean process needs to operate in an environment that contains:

• A longer term view (sufficient to flex major capacity step changes).
• A knowledge of the current inherent unreliability and flexibility of their processes and supply chain.
• Sufficient stock or capacity buffer to accommodate this variability.

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Finally here is a question for you:

How much stock is required to buffer two successive, adjacent, processes of equal capacity with 99.9% reliability, working at their capacity? (It rarely gets better than this!)

Answer

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The following further best practice articles were also mentioned in this paper:

The following public training courses and in-house workshops provide routes to Lean Manufacturing:

To discuss your consulting or training needs with one of our independent consultants or trainers please Contact Us.

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©SM Thacker & Associates (Consultancy and Training Specialists) Original November 2000, Version 10 November 2009