Uploaded 31 Jan @ 15:38pm
Until relatively recently, manufacturers classified waste as any material remaining on the factory floor, flushed into a plant’s effluent stream or vented into the atmosphere, while creating their products. Faced with rising costs and an influx of cut-price products, a growing number of local producers have been moved to rethink this limited definition of waste. Empowered by this new insight, they are reaping some valuable benefits. Mel Dunkin reports.
In addition to raw materials; technology, finances, time and human capital are all crucial to the production process. Under the terms of this new paradigm, if the manner in which any one of these resources is used results in activity that adds cost without adding value, such activity is considered to be avoidable waste. The key to its elimination lies in the application of lean manufacturing principles.
Studies conducted by Cardiff University’s Lean Enterprise Research Centre suggest that, from a consumer’s perspective, as much as 60 per cent of the activity undertaken by manufacturers adds no value and therefore amounts to costly and unnecessary waste.
Seven sources of waste
While that figure sounds alarming, there are many ways in which any company can substantially reduce these counter-productive activities. In practice, the possible interventions are almost limitless and, as their effects are cumulative, they should form part of an ongoing strategy.
The fundamental principles of lean manufacturing are driven by seven distinct sources of potential waste. Most, if not all, companies could manage such waste far more effectively.
Many manufacturing tasks remain labour-intensive. In such cases waste is easily identified and, invariably, just as easily overcome. For instance the placement of tools and workpieces can often be optimised so as to eliminate all unnecessary bending, stretching or walking, thus saving time, reducing fatigue and improving productivity. Rather than resorting to the formal time and motion studies of the past, lean principles encourage workers to point out instances of superfluous movement and to suggest how they could be reduced or eliminated.
Holdups while waiting for parts, for repair or servicing of machinery or simply for a process to complete, can seriously impede productivity and add significantly to costs. Easily spotted, component shortages can be rectified by standardising internal handling of parts already on site but not delivered to the production line or through improved ordering and inventory control, for parts not yet on the premises.
While machine downtime is also readily seen and controlled with a sound programme of preventative maintenance, it is often harder to spot unnecessary waiting time inherent in a given process. However, where operators are forced to wait for a process to complete before resuming their activities, a more productive option could be to use that waiting time for other operations.
Fearing the effects of shortages, many companies tend to carry excess inventory ranging from finished goods and sub-assemblies to raw components, office supplies and spare parts. While this tactic may obviate shortages it also creates a demand for additional storage space, limits the company’s cash flow and adds to the burden of warehouse staff responsible for movement and rotation of stock.
A closer review of actual usage in each of these areas, together with parallel improvements in production control will lead to significant reductions in lead times and inventory levels with corresponding savings.
Transporting materials of any kind contributes to manufacturing costs yet adds no value to the end-product. It occurs in production and delivery areas, and at all points along the supply chain, increasing cycle times or overall lead times.
Simply maintaining a small stock of components closer to where they are used could reduce the time spent making longer journeys between the workplace and the warehouse. The same principle applies to delivery areas. Raw materials and components should be delivered directly to the plants in which they will be used and not re-transported from storage facilities at sister sites.
To minimise waste on-site and off, vehicles should never travel unloaded, so each trip should combine deliveries with collections.
Allowing production to continue when existing order levels do not justify it, rather than ceasing production, is a common source of waste. Overproduction creates a need for more storage and handling and also carries the risk of eventual obsolescence.
In practice, closing a production line can have benefits. It allows time for cleaning, preventative maintenance and for workers to identify wasteful activities and test possible remedies.
The quest for excellence often leads to excessive processing. For example, hidden parts of an assembly may undergo trimming that is not crucial to their performance, adding to cycle times. Just 2 seconds shaved from a 20 second cycle could produce an extra 160 units over the course of an 8-hour shift.
When missed, the consequences of product defects can be far-reaching. As well as the cost of reworking, salvaging and scrapping defective items, should these be released into the market, it could mean lost clients and jeopardise future sales. The lean philosophy is to incorporate pre- and in-production quality controls as well as post-production measures.
Automation in Lean Manufacturing
When optimising manual operations, the potential of automation to facilitate lean manufacturing is clear though often overlooked. Automation offers a level of speed, precision and reproducibility beyond that of a human machinist.
For example, wireless connected machines can, through the internet of things, eliminate waste in many areas such as inventory control, maintenance scheduling, use of transport and maintaining realistic production levels based upon known demand.
In keeping with the intended spirit of lean, automation should not lead to employee redundancies. Instead, it should release workers from mundane, repetitive tasks to pursue more productive roles in keeping with their full potential, thus optimising the return on a company’s investment in human capital.
Implementing lean principles will require a plan and what could be more appropriate than the Japanese ‘5s’ methodology applied to just-in-time manufacturing. Based upon five Japanese words with the initial letter ‘s’, these translate roughly as clearing, organising, cleaning, standardising and training. Each should form part of a plan with realistic milestones and deadlines.
It is a good idea to start with a single division of the business, focusing on just one of the seven types of waste at a time and using the measureable improvements achieved as the means to motivate the staff of other divisions to embrace lean concepts.
Standardisation is perhaps the most powerful of the 5s components. When workers are directed to perform their tasks in a repetitive manner, it becomes far easier to spot waste and to test various ways to minimise its effects.
Most importantly, implementing lean principles should not be seen as some kind of once-off, major overhaul. Instead, it should become an ongoing culture in which the aim is one of continuous improvement. Known as Kaizen in Japanese, its ultimate goal is the elimination of all waste.
Although the focus of this article is on manufacturing, the applications for lean principles extend far beyond the factory floor. The need to do more with less is no less evident in the office environment, in retail, in construction and even in education and healthcare.
In the changing global economy, eliminating wasteful activities could soon become crucial, not just to an organisation’s efficiency, but to its continued survival.
Ben Hayes – Sales Manager, CWST
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