By Nick Tyler, Managing Director, The Tube & Bracket Company. Mention “lean” to most people in manufacturing and there’s a good chance they will tell you it’s too complicated, not worth the effort or better applied to other types of business. Strange sounding jargon such as Six Sigma, Kaizen and Kanban doesn’t help sell the idea and the terminology can be about as revealing as the names in the latest Ikea catalogue. But scratch beneath the surface and it’s clear that the principles involved can be applied to almost any production environment because they are about simplifying and eliminating wasteful processes. And at their heart is the idea of optimising the handling and storage throughout the production chain and especially at the lineside.
Special video sequences and a new booklet available from The Tube & Bracket Company provide simple but graphic illustrations of how lean manufacturing storage and handling techniques can be applied to virtually any manufacturing process to deliver significant performance improvement and reduce overall costs.
One of the core objectives of lean manufacturing is continuous improvement. Making small modifications to a process or activity whenever required can lead to significant and sustainable performance improvement over time. Another core objective is reducing or eliminating wasteful or inefficient processes – “muda” in the jargon. Some commentators suggest that 80 per cent of lean manufacturing is about removing muda. There are seven different muda that impact on a manufacturing process and inefficient handling contributes to them all.
Traditional manufacturing involves handling large pallets or containers and inventory batches that are inherently wasteful. Items must be stored and handled relatively frequently which involves large warehouses and special materials handling equipment, all of which adds to costs.
The overall process “pushes” inventory through the system which can lead to overproduction. Lean manufacturing looks at the issue from the other perspective and aims to align output with demand using “pull” orientated concepts such as Kanban and just-in-time. Minimising inventory, storage and handling is the key because – the argument goes – if they aren’t needed to produce an item now why are they at the factory?
A different approach involves using modular and adaptable workstations, carts, trolleys and lineside storage facilities to create a highly efficient production environment where everything is designed to promote efficient and ergonomic working. The inherent adaptability and flexibility of the modular equipment supports continuous improvement because modifications can be made at any time to reduce muda and drive better processes. So far, so good but how does this relate to the seven muda and what does this mean for the manufacturer?
Unnecessary Stock Muda: raw materials, work in progress and finished product ties up valuable capital into the production chain when it could be released for better uses within the business. Handling and storage uses valuable space, takes up time and resources and adds even more costs. Shortening production lead times and reducing handling and storage tasks releases capital and cash. This can be achieved by aligning production to demand so products leave the factory (and are invoiced) as soon as they are ready. Deliveries of raw materials must be arranged to coincide with when they are needed at the lineside. At the most extreme this means taking deliveries of supplies just-in-time straight to the lineside to minimise handling costs and eliminate storage needs.
The use of adaptable carts and trolleys designed to carry precise numbers of specific items to the lineside helps eliminate this muda. So does the use of modular parts supermarkets positioned at the lineside and replenished frequently when stocks fall below predetermined levels. In practice, many companies operate small buffer warehouses that feed the lineside, allowing them to combine the economy of scale benefits of batch deliveries with the super-efficiency of just-in-time lineside replenishment.
Defect/Reject Muda: defects cost time and money. Returned items must be fixed and this affects customer perceptions and service. Disposing of rejects adds more cost. The easiest solution is to avoid making bad products. Adaptable ergonomic workstations matched to the specific process can be designed and built where components, assemblies and tools are in the correct position and easy to reach. This makes the working area much more efficient and staff are more productive and less stressed or fatigued which means they are less likely to make mistakes and damage items.
Unnecessary Movement Muda: Unnecessary movement in the working area adds to the time taken to complete a task which reduces productivity and adds to costs. Workstations and storage areas should be designed ergonomically so that items are close to hand whenever they are needed and so avoid time-consuming steps and movements to fetch or reach for them. Production staff have fewer distractions and are then less likely to make mistakes which helps improve quality. Adaptable workstations and parts supermarkets can be designed to take up the correct space – no more, no less – to accommodate the process. This also helps increase overall production density because more production areas or cells can be fitted into the same space.
Overproduction Muda: overproduction occurs when manufacturing schedules are misaligned with demand. Introducing customer-focused “pull” scheduling through use of just-in-time or Kanban principles helps ensure that products are produced to the customer’s specification when they are needed. Adaptable parts supermarkets and the use of carts, trolleys and trains to supply the production line or cell promote flexibility and enable production to be modified very quickly to match changing customer demand.
Transport Muda: moving products from one place to another adds no value and uses up capital and space. Lean manufacturing reduces the amount of handling required to support any given process and minimises the distances between points such as the loading bay, lineside or workstation so that less time and space is utilised. Adaptable carts and trolleys can be designed for handling specific products but can be modified if the items change.
Waiting Muda: production staff waste time waiting for replenishments if they run out of components. Lean manufacturing aims to ensure a steady flow of items to the lineside, not too many and certainly not too few, to allow production to continue without interruptions. Installing lineside parts supermarkets which are replenished regularly helps avoid the problem. Larger items can be brought to the lineside or workstation when they are needed using adaptable carts and trolleys.
Inappropriate Processing Muda: any task that can be eliminated without affecting the production of an item is wasteful. For example, using small front-picked containers reduces the length of the production line, optimises pick paths, reduces flow costs and saves time. And making an installation smaller generally makes it less expensive to build in the first place.
Efficient handling and storage has a role in reducing each of the seven muda identified in lean manufacturing. These are highlighted by special video sequences and a new booklet available from The Tube & Bracket Company which show real lean manufacturing operations in action. Using simple, real-life applications the video and booklet help to show how lean manufacturing handling and storage practices can be applied to any manufacturing process to deliver performance improvement with reduced overall costs. Manufacturers also become more agile and responsive to customer demands, allowing them to provide greater levels of service without compromising their own business objectives.
The Tube & Bracket Company Limited
Nick Tyler
Tel: 01295 277791
Email: sales@tubeandbracket.com
www.tubeandbracket.com
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