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Lean Operation, Looking for waste, Waste type continuation, Muda, Mura,…
Lean Operation
Consideration of flow
- Between each stage, it is the downstream customers stage that signals the need for action
- This customer pull encourages items to flow through the process in a synchronised manner (rather than dwelling in inventory)
- The smooth, synchronised flow and resulting reduction in inventory affects the motivation to improve because stages are no longer decoupled
- The increased motivation to improve exposes waste and encourages its elimination
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Waste
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Causes of waste
Muda – these are activities in a process that are wasteful because they do not add value to the operation or the customer.
Mura – this means ‘lack of consistency’ or ‘unevenness’, which results in periodic overloading of staff or equipment
Muri – this means ‘absurd’ or ‘unreasonable’. It is based on the idea that unnecessary or unreasonable requirements put on a process will result in poor outcomes
Types
Waste from irregular flow perfect synchronisation means smooth and even flow through processes, operations, and supply network
Waste from inexact supply (perfect synchronisation also means supplying exactly what is wanted, exactly when it is needed)
Waste from inflexible response (customer needs can vary; however, processes usually find it more convenient to change what they do relatively infrequently because every change implies some kind of cost)
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Philosophy
This is the coherent set of principles that are founded on smoothing flow through processes by doing all the simple things first, gradually doing them better, on meeting customer needs exactly and (above all) on squeezing out waste every step of the way
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Consideration of people
Lean proponents frequently stress the importance of involving all staff in the lean approach (encourage a high degree of personal responsibility, engagement, and ownership of the job)
basic working practices are sometimes used to implement the involvement of everyone principle, which include the following
Discipline – work standards that are critical for the safety of staff, the environment, and the quality must be followed by everyone all the time
Flexibility – it should be possible to expand responsibilities o the extent of people’s capabilities
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Autonomy – delegate responsibility to people involved in direct activities so that management’s tasks become one of supporting processes
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Development of personnel – over time, the aim is to create more company members who can support the rigors of being competitive
Quality of working life (QWL) – this may include involvement in decision making, security of employment, enjoyment, and working-area facilities
Creativity – this is an indispensable element of motivation. Creativity, in this context, means not just doing a job, but also improving how it is done, and building the improvement into the process
Total people involvement – staff take on more responsibility to use their abilities to the benefits of the company as a whole.
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Planning and control
Many lean ideas are concerned with how items (materials, information, or customers) flow through operations; and, more specifically, how operations managers can manage this flow.
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The focus of this is to achieve a flow of materials, information, or customers that delivers exactly what customers want, in exact quantities, exactly when needed, exactly where required, and at the lowest possible costs
Looking for waste
The 5S method
thought of as a simple housekeeping methodology to organise work areas, which focuses on visual order, organisation, cleanliness, and standardisation
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Straight (Seiton) – Position things in such a way that they can be easily reached whenever they are needed
Shine (Seiso) – Keep things clean and tidy, no refuse or dirt in the work area
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Streamlined flow
The smooth flow of material, information, and people in the operation is a centra idea of lean synchronisation
This is because long process routes provide opportunities for delay and inventory build-up, add no value, and slow down throughput time. And so, the first contribution an organisation can make to streamlining their flow is by reconsidering the basic layout of the process
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Visual Management
designed to make the current and planned state of the operation or process transparent to everyone, so that anyone (whether working in the process or not) can very quickly see what is going on
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Gemba walk
(also sometimes called Ganba), when roughly translated from Japanese means the actual place where something happens
It is a term often used in lean philosophy or in improvement generally, to covey the idea that, if you really want to understand something, you go to where it actually takes place.
Throughput time
the longer that items being processed are held in inventory, moved, checked, or subject to anything else that does not add value, the longer they take to progress through the process.
Value-stream mapping (also known as end-to-end system mapping) is a simple but effective approach to understanding the flow of materials and information as a product or service has value added as it progresses through a process, operation, or supply chain
This is similar to process mapping, but is different in four main ways
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It often has a wider scope, frequently spanning the whole supply chain
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A value-stream perspective involves working on (and improving) the big picture, rather than just optimising individual processes
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Flexible processes
Responding exactly and instantaneously to customer demand implies that operations resources need to be sufficiently flexible to change both what they do and how much they do for it without incurring high cost or long delays
Reducing changeover time
Methods
Measure and analyse changeover activities – sometimes simply measuring the current changeover times, recording them, and analysing exactly what activities are performed can help to improve changeover times
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Convert internal and external activities – to convert work that has previously performed during the changeover to work that is performed outside the changeover period
Prep-prepare activities or equipment, instead of having to do it during changeover periods
Make the changeover process intrinsically flexible and capable of performing all required activities without any delay
Speed up any required changes of equipment, information, or staff (using simple devices)
Practise changeover routines – the constant practise of changeover routines and the associated learning-curve effect tends to reduce changeover time
Minimising variability
The first cause of variability to consider is the mix of items moving through processes, operations, or supply networks
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Waste type continuation
IF
Waiting time - Machine and labour efficiency are two popular measures that are widely used to measure machine and labour waiting time, respectively
Transport - Moving items or customers around the operation, together with double and triple handling, does not add value
Process inefficiencies regardless of type, all inventories should become a target for elimination; however, it is only by tackling the causes of inventory or queues, such as irregular flow, that they can be reduced
Inventory - regardless of type, all inventories should become a target for elimination; however, it is only by tackling the causes of inventory or queues, such as irregular flow, that they can be reduced
Wasted motion – an operator may look busy, but sometimes no value is being added by the work
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Muda, Mura, Muri
Muda
Main cause
poorly communicated objectives (including not understanding the customer’s requirements), or the inefficient use of resources
Implications
that for an activity to be effective, it must be properly recorded and communicated to whoever is performing it
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Muri
Implications
appropriate skills, effective planning, and accurate estimation of times and schedules will avoid this muri overloading waste
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