The new generation of lean production building kit systems

Guidelines and practical tips for building and using cost-effective factory equipment

The principles of lean production have changed industry forever and boosted both erformance and flexibility in industrial manufacturing. However, that is no reason to settle for the status quo – as the name suggests, continuous im rovement never stops. As methods are honed, roduction systems are also taken to the next level. Ex erience with lean roduction building kit systems has been fed into technical advances, which in turn have hel ed com anies to com lete many tasks faster, more efficiently and more cost-effectively than in the ast. Today, thanks to cutting-edge fastening technology, roduction staff can build trans ort trolleys, racks and shelving units that are much more robust and yet can still be modified quickly and with relatively little effort.
This White a er summarizes the basic rinci les of lean production and ex lains which methods have roven useful in ractice. Des ite increased demands, next generation solutions can still deliver rogress in the fight to eradicate inefficiency in roduction. Cutting-edge lean roduction building kit systems are an extremely effective tool when seeking to achieve continuous im rovement.

1. Benefiting from next generation lean production building kits

An MIT study conducted between 1985 and 1991 revealed that Toyota performed much better compared to other car makers worldwide. The Toyota Production System, which set new standards in terms of throughput time, quality, costs and flexibility, was identified as one of the main reasons for the company’s outstanding performance. The obvious benefits of this system spurred on companies and researchers around the world to analyse, adapt and enhance the principles on which it was based. The consequences were far-reaching – so much so that the basic tenets of modern business management with quality management and continuous improvement can be traced back to the lean production concepts developed at Toyota. Today, the boundaries between conventional and lean production are no longer clearcut.

The widespread use of lean production has not only helped refine the associated methods, it has also ensured the continued development of the tools and equipment used to put it into action in the workplace. Experience with shortcomings, additional application areas and a whole range of individual improvement measures have ensured that the new generation of lean production building kit systems is much more efficient and robust than its predecessors.

This White Paper shows how companies can benefit from the technical advances in lean production building kit systems. The special system solutions that support the on-site construction of shelving units, racks, transport trolleys and conveyor lines enable personnel to improve their working environment independently, without the need for centralised planning arrangements. Production equipment and facilities can now be built faster, with more elegant results and more economical material usage than can be achieved with first generation systems. What’s more, reusing and modifying existing frames is usually a more straightforward affair.

The new generation of lean production building kit systems is proof that continuous improvement and consistent optimisation can help lower the consumption of resources. Companies also need to be willing to move away from the attitude that triedand-tested working methods ought to be preserved forever. All methods need to be continuously scrutinised and replaced with more efficient alternatives as and when necessary. For example, using a cutting-edge lean production building kit system instead of a first generation solution can halve the amount of time needed to build a transport trolley. Moreover, work that previously had to be done by two members of staff can often be done by just one.

The first section of this White Paper explains the principles of lean production and the role that building kit systems play when it comes to putting these principles into action. The second section focuses on the practical side of how companies that make consistent use of lean production technologies can save time and money without compromising on quality and durability.

2. How it all began – the origins of lean production

Improvement, increased efficiency and innovation are what keep the wheels of the economy turning. Success means satisfying customer demands while using your own resources as economically as possible – balancing costs and benefits is simply good business sense. In production, the aim is to achieve as short a throughput time as possible while ensuring high quality standards for customers. One of the key messages of quality management pioneer William Edwards Deming, who advised Toyota, was that costs automatically drop when companies pursue short throughput times and excellent quality. This can be achieved by using new processes and technologies and also by organising processes logically. At the end of the 19th century, pioneers such as Frederick Taylor and Frank Gilbreth developed efficient production as a separate branch of research. At a time when most companies were reliant solely on the inventiveness of their entrepreneurs, Taylor and Gilbreth developed the concept of scientific management, which optimises each individual activity and integrates the work capacity of each employee into the overall process.

In 1913, Henry Ford kick-started the most intense phase of the second industrial revolution when he introduced the concept of focussing on the flow of processes. The conveyor belt became a symbol of the industrial age. Conveyor-belt production, standardised mass-market products and specialised machinery were seen as the best ways to drive down unit costs even further and make products affordable for more and more people.

However, some ten years after conveyor belts had revolutionised production forever, the first problems started to appear. While customers increasingly wanted cars that were different, Ford, in his book “My Life and Work”, insisted that “any customer can have a car painted any colour that he wants so long as it is black.”

Due to the growing diversity of product variants and the tendency toward smaller batch sizes, costs exploded in traditional Ford-style mass production, which is geared toward optimising unit costs. This was in part due to the long and complex changeover procedures. The advantages that Ford enjoyed by manufacturing just one model with short throughput times and no major changeovers in the production line now turned out to be disadvantages. The response from General Motors was not to try and improve traditional Ford-style mass production, but to invest in new factories and set up a dedicated production plant for practically every new variant released.

Toyota took a different approach – continuous improvement. They asked themselves how they could maintain Ford’s notion of a production flow without the money to invest in new factories and machinery. The only option was to manufacture all the variants on existing machinery in the existing plant, but to make that happen with as little downtime as possible, makeready times would have to be reduced. One prominent example was the instruction given by a high-ranking Toyota manager that the setup times for bodywork presses should be reduced from several hours to a few minutes. The approach invented at Toyota to achieve that aim is now known as the SMED (Single Minute Exchange of Dies) method. It took around 20 years and continuous improvement using PDCA before the ambitious target was met.

Toyota has been practising this continuous improvement approach since the 1950s. Over the years, Toyota employee Taiichi Ohno developed an organisational structure with coach/coachee relationships as part of a line organisation. In this concept, team leaders (Hanchos) are responsible for improving the processes they work on with their team of up to five staff members. That could be on a line, a machine or at an assembly work bench. To reduce capital lockup, Ohno also integrated suppliers closely into in-house production planning. Achieving trusting cooperation between the customer and its suppliers, including coordination on production planning (Ohno’s preferred model) was no easy task. It was much more complicated to put into practice than the traditional approaches used by other companies at the time – and by many companies to this day – whereby suppliers are simply required to satisfy customer specifications without any coordination or collaboration. To some extent, it still is a difficult task. Toyota’s solution was based on the pull principle, which states that the flow of materials is dictated not by the speed of the production line or machine, but by sales. Production adapted to demand and was optimised so that it could respond to changes flexibly. A system of continuous improvement and adaptation to changing customer requirements thus developed under Ohno’s guidance. This meant production methods could be refined on an ongoing basis instead of in stages, and that is the core of modern-day lean production and its familiar methods, such as 5D, Kanban and SMED. These tools enable companies to respond faster to changes and therefore be more agile on the market.

Since the 1980s, the Toyota Production System has also been modified outside Japan. It took around 30 years for the benefits of lean production to become so compelling that companies across the entire world started to study and adopt the approach. Another 30 years later, principles such as continuous improvement and consistent quality management have become standard for cutting-edge production. However, lean production is still being developed. Numerous companies and universities are studying the issue of how the lean philosophy can be made a central element of company management. All this experience is feeding into the next generation of lean production, which sees managers as coaches for their employees, with Kata ensuring everyone is constantly learning, and developing their skills and their production environment. The term “Kata” describes a routine that is repeated over and over to make a certain activity second nature and originates from marital arts, where it refers to a specific sequence of movements. At Toyota, Kata are used to coach employees (coaching Kata) and continuously improve processes (improvement Kata). And since continuous development is a key feature of this attitude and approach to work, that is precisely how it should be.

Continuous improvement – never being satisfied with the status

The lean term “Kaizen” is made up of the Japanese words for “change” (Kai) and “for good” (Zen). Kaizen is the attitude that sees improvement as a neverending process because it is not possible to be satisfied with the status quo. No area is unimportant or impossible to improve – you just need to look closely enough. Swedish manager Jan Carlzon summed up the principle with these words: “You cannot improve one thing by 1000 percent but you can improve 1000 little things by 1 percent.”

Today, the continuous improvement process (CIP) is part and parcel of every state-of-the-art production system. In order to make continuous improvements in small steps, companies have to combine expertise with responsibility. While Taylorism regards the worker as a small cog in a big machine, CIP gives the specialists on site the freedom to introduce changes on their own initiative. That means giving workers the tools and the authority they need to deliver gradual improvements in a stepby- step process. Lean production building kits are system solutions that make it easy for users to build shelving units, racks, transport trolleys and other factory equipment. Ideally, a CIP workshop will be incorporated into a company’s production system so that teams of workers can use it as and when they see fit.

The cumulative improvements this workshop helps to deliver are not cost-intensive and enable the teams to try out new methods, even if they turn out to be flawed. Investing in small steps like these is important and, far from being wasteful, this approach counts as essential research into new methods.

However, continuous on-site improvement is always just one of several measures. CIP is the central principle of the lean philosophy and is also tied into quality management to DIN ISO 9001, where it is seen as complementing ideas management and suggestion schemes.

Rapid response – the role of the lean production building kit system

One of the recipes for success in lean production is maintaining a consistent focus on the value-added chain and processes. This ensures maximum transparency. All processes are regularly reviewed to identify opportunities for improvement, which in the ideal scenario helps keep changeover times short whenever processes need to be modified. This flexibility is decisive when it comes to reacting quickly to new production specifications, customer requirements and necessary increases in production capacity.

Companies that can rapidly integrate new products, improved versions or additional variants into the production process have an edge on the competition. However, whether large or small, changes require alterations to factory equipment. Lean production building kit systems give companies the option of building the frames or trolleys they need on site, without having to first work through a tedious planning process that drains manpower. The continuous improvement process is based on the belief that the teams who know the products and processes should be able to develop solutions independently and put them into practice directly in the CIP workshop. The first generation of lean production building kit systems satisfied the basic requirements. They were predominantly based on plastic-coated steel tubes that were simply cut to size and connected together with fasteners to build the desired equipment.

As the principles of lean production started to take hold, though, the requirements on lean production building kit systems started to increase. As the systems were put to greater use, three key problems often came to light:

1. Complex and costly modifications: Lean is the philosophy of continuous improvement, which means it is essential that factory equipment can be quickly and easily adapted to optimise processes. The use of specialised fasteners for intersection points – which is still a common practice in many systems – means that many modifications, such as repositioning a tube or disconnecting it from an intersection point, cannot be made without complex rebuilding work. With the mistakes of the past now learned, new lean production building kit systems have come onto the market, ready to meet the increased demands. These systems are based on aluminium, do not feature a plastic coating and enable long-lasting, stable connections. One-man assembly is also possible, as are subsequent modifications. All this helps companies develop the improved speed and flexibility that lean production demands.
   In practice, state-of-the-art lean production building kit systems save a great deal of time and help meet the need to actively support continuous improvement. They therefore offer the ideal tools for eradicating all types of waste in production. Alongside an unrestrained focus on the customer that is achieved through maximising quality and ensuring rapid adjustment to market requirements, the fight against waste is central to lean production.
2. Poor durability: The combination of plastic and steel results in creep behaviour, which means fasteners have to be retightened on a frequent basis. Continuous maintenance work is required when equipment is being used over long periods.
3. Complex assembly: Fasteners usually form intersection points for two to five tubes. All the individual parts need to be held in position and screwed tightly in place at the same time, which often requires two people.

3. Lean production – The seven principles against waste

Customers pay for the added value generated during production – not for unnecessary activities. This makes throughput time a decisive factor in lean production – one that is determined by three factors: Muda (waste), Muri (overloading) and Mura (imbalance). Processes need to be standardised, stabilised if necessary and then optimised. This reduces costs without compromising on quality. Indeed, the only processes that are eliminated are those that use up resources without contributing to the value of the product. The seven types of waste (Muda) help define the scope for improvement in production. This Japanese term means an activity that is pointless and describes a lack of purpose or sense. Although the fight against waste, which can often be difficult to identify, is more tangible than the somewhat more abstract concept of efficiency, it is an activity that nonetheless aims to boost the cost efficiency of production systems. All the same, the relationship between a company’s outlay and return doesn’t offer any really clear indications of where waste can be eliminated. Lean production focuses on a company’s outlay and sets out to counter all types of waste.

The seven principles against waste relate to:

1. The movement of materials
2. Stock levels
3. Movement
4. Waiting times
5. Processing
6. Overproduction
7. Rectifications and errors

The following pages of this White Paper explore the detail behind the principles of lean production and how a lean production building kit system can help companies put in place the necessary methods.

Avoiding unnecessary movement of materials

Important resources are used every time a workpiece is moved from one place to another. After all, no value is added to a workpiece while it is being transported, as the throughput time gets longer without the value of the product increasing. Instead, extended capital lockup and additional outlay in terms of energy and personnel means that costs increase. What’s more, each time something is moved, it is put at greater risk of being damaged or suffering quality impairments. The potential for waste exists in every single aspect of an internal logistics system. Or, to put it in a more positive light – internal logistics offers huge potential savings!

A lot of waste can be prevented by carefully planning the individual steps in a workflow, and that includes arranging the various locations where work is carried out so that they are closer together. At the same time, the individual processes themselves need to be coordinated with each other. The aim of value stream mapping (VSM) is to optimise throughput times and synchronise individual stages in a workflow. This includes taking into account set-up times when different products are being made on the same machinery or at the same work benches. Working on the basis of an optimum material flow produces important indications for how to cut waiting times and shorten transport routes. One of the aims of lean production is to reduce the movement of materials, manage it in a more efficient way and thereby reduce throughput time. The latter can be achieved by using intelligent interlinking systems between workstations and customised transport solutions. The new generation of lean production building kit systems therefore offers a single system for intralogistics and frames that ensures a smooth transition between work stages and transport stages. Using aluminium tubes with stable aluminium fasteners results in strong holding forces that are not impacted by dynamic loads and therefore have a positive impact on durability. Furthermore, stable constructions can be built with less material. State-of-the-art fastening technology withstands many thousands of load changes without screws having to be retightened.

Transport trolleys made from welded steel frames are usually very heavy. A cutting-edge lean production building kit system can be used to build stable yet lightweight aluminium frames, meaning that internal logistics teams can save energy.

Minimising stock levels and warehousing

High volumes of goods in process are often a warning sign for problems in production planning. They can have many causes such as overproduction, waiting times and unnecessary movement of materials, and these need to be subjected to thorough analysis. They also need be resolved at the same time, as high stock levels can often mask other problems. Simply reducing stock levels would only exacerbate the consequences of the underlying problems in the workflow. The aim is to standardise, stabilise and optimise production processes so that stocks of preliminary and intermediate products can be reduced.

However, even if the stated goal is to achieve a “one-piece flow”, there still needs to be a certain volume of stock to protect against fluctuations. The art lies in getting that volume just right and continuously monitoring the actual flow of materials based on feedback.

The Kanban principle is often used as a means of managing sequences. Kanban is a Japanese word meaning “sign-board” or “billboard” and describes a simple method for ordering materials based on actual consumption. Kanban systems use cards to provide information on which locations are running low on stock. Included with every delivery, these order cards clarify the current flow of goods in line with the pull principle. This helps companies to minimise stock levels of the preliminary products required at the production site. One of the typical applications of lean production building kit systems is the construction of Kanban trolleys that enable operators to quickly resupply workstations. Next generation building kit systems also apply the principles of lean production to themselves. Experience has shown that the “one fastener for all” principle helps to keep warehousing requirements low. Instead of having to stock a whole range of specialist fasteners for various scenarios (connecting together 2, 3 or 4 tubes), companies can complete all their engineering tasks using just one standard product for 90° connections. Only a few of these fasteners need to be held in the CIP workshop, since modern logistics systems can deliver additional supplies quickly. Suppliers with excellent global supply availability help their customers to reduce these costs. A good supplier will even be able to deliver specialised components in the desired quantity in just 24 to 48 hours.

Preventing superfluous movement

“Only the last turn of a bolt tightens it – the rest is just movement.” This quote from Shigeo Shingo, who helped develop the Toyota Production System, neatly sums up this type of waste. If a company wishes to cut out waste, it has to focus on the movement in the production sequence that actually generates added value.

Employees having to repeatedly lean over or bend down to reach consumables, fastening points that are difficult to reach, and workpieces located at an unergonomic working height – all these require unnecessary movement. The additional time taken up by each individual reaching movement adds up to a significant wastage of working time. The same applies to time spent looking for working materials. Arranging material crates so that they are in easy reach and ensuring workpieces are at the correct working height saves time. Preventing superfluous movements usually also improves the ergonomics of a work bench. Unnatural postures and reaching distances that are too high or too low put strain on an employee’s muscles and bones. By contrast, ergonomic work benches take into account the optimum handling area for the individual operator working at them. This prevents fatigue and uneven strain, thereby also improving safety levels.

Next generation lean production building kit systems make the construction of factory equipment as straightforward as possible, even ensuring that assembly work can be completed by a single person. Every strut is inherently stable because it is fastened individually, which is a clear advantage over previous systems that fastened numerous tubes together in special intersection point fasteners.

Reducing waiting times

A successful production system is based on carefully planned sequences. Valuable working time is lost if a workstation has to wait for workpieces or specific bolts and screws. And you can’t expect people to wait for a machine. The same applies to machine downtimes and other technical problems. The principle of keeping waiting times down is in direct conflict with the need to keep stock levels as low as possible. Oversupplying materials and spare parts is no way to improve overall productivity.

To reduce waiting times, companies need to achieve the right mix of standardised processes, clear lines of communication and flexibility based on independent organisation. After all, it is not possible to plan for all eventualities, and centralised planning usually takes too long and incurs excessive costs.

That is why, in lean production, solutions are put into action onsite at the work bench or workshop, which is often referred to as the “gemba”. Employees know best which tools and equipment they need and can develop these solutions themselves using a lean production building kit system. Cutting out waiting times also improves efficiency. Fasteners that are supplied preassembled speed up work as they simply need to be put in place and tightened, thereby eliminating the need to fit together numerous individual components, thus saving time. In the past, when subsequent modifications had to be made at complex intersection points, the entire connection would have to be disassembled, even if just a single strut had to be moved. When using state-of-the-art solutions, users can add reinforcements virtually anywhere they like, whenever they need to. This means companies don’t need to stock too much material as a precaution and can cut the waiting time for planning and making modifications. Because fasteners create a stable, rigid connection, cantilever arms can be added in a matter of seconds so that tools and similar elements can be suspended in the handling area. The work can even be carried out in situ if the user has sufficient experience with the system. Eliminating a whole range of different profile fasteners makes on-site warehousing and reordering much easier.

Eliminating complex processing

Heavy lifting, difficult to reach materials, unnecessary worksteps – these are just some of the many different ways that time and money are wasted in production processes. This type of wastage can usually be traced back to superfluous processes or excessively complex sequences. The tools have to be right for the job.

When applying lean production methods, companies should start by planning for the minimum and then improve the existing infrastructure gradually. This prevents overengineering and retains flexibility. If the design allows, a basic frame can always be modified later on so that it can be extended. It is not uncommon in lean production for plants to be used over a long period of time, being gradually modernised with add-ons and extensions.

Next generation lean production building kit systems are therefore based on a small number of basic elements that can be adapted and extended as necessary using highly specialised elements. This safeguards flexibility. Planning for the minimum means users can subsequently improve designs to suit their application. For example, a frame or transport trolley can be modified for specific requirements with relative ease and does not therefore have to be built larger or stronger than strictly necessary in the first instance.

Experience has shown that the plastic coating on steel tubes, which is typical of first generation systems, exhibits less resistance against displacement forces. The end result is that frames have to be built with more material than necessary so as to ensure long-lasting stability. What’s more, the creep behaviour associated with plastic-coated steel tubes means that screws have to be retightened on a very frequent basis. Any damage to the plastic coating exacerbates this effect, while the exposure of sharp edges also represents a significant risk of injury.

Next generation solutions include stable aluminium fasteners, use flexible foam tube protectors that are fitted separately and produce constructions that are exceptionally durable.

Overproduction is the worst type of waste

Producing goods earlier or faster than is strictly required by the next process leads to the overproduction of preliminary, intermediate and final products. Overproduction is also referred to as the worst type of waste because it brings about many more types of waste. These include additional transport, more rejects, more reworking and high stock levels.

On the one hand, a targeted material flow requires accurate feedback to production about how much output is currently required. On the other hand, the sequencing of processes must not be too rigid (see page 8). All in all, production has to be flexible enough that it can adapt to the actual take-up of products (pull principle). Being able to restrict, increase or convert production systems is one of the main aims of lean production when it comes to preventing overproduction. This is usually easier to achieve with small, flexible units than with monolithic systems, which are only efficient when producing high unit numbers all the time. From a lean viewpoint, a manual but flexible system comprising a building kit system will therefore always be preferred over an automated variant. The ability to make quick, simple adjustments to factory equipment and work benches ensures companies can adapt the volumes produced, the required level of variation and the delivery time to suit customer demand.

A lean production building kit system supports this essential flexibility on site at production. It enables users to easily convert workstations and reconfigure them as required. An adaptable system that grows with a company’s needs is open to change and extension – the key to success lies in being able to reuse systems without limiting their functionality.

When using state-of-the-art lean production building kit systems, constructions don’t need to be completely disassembled before additions can be incorporated at intersection points – add-on components can be integrated as and when required. It is the fasteners in next generation building kit systems that make this possible, as they can be added at any position on a structure. The “one fastener for all” principle ensures that existing constructions never fall out of use, because they can be extended and reconfigured to suit requirements. For example, the incline on a roller conveyor can be adjusted to suit the dead weight of workpieces in a few simple stages and, since assembly work is straightforward and can be completed by a single person, frames and carriages can be built and modified in next to no time.

The right way to handle rectifications and errors

Rectifications and errors tend to be frowned upon in classic production systems. They need to be avoided at all costs, since every error impacts on quality and profitability. By contrast, lean production boasts a fault culture that strives for perfection by learning from mistakes. This is something companies can only do when they actively engage in the process. Every error that is discovered is valuable because it represents an opportunity for long-term improvement. Nothing could be worse than declaring production problems completely taboo and thereby encouraging everyone to overlook and ignore them. As a methodology, it demands that companies keep a close eye on all work stages, ensuring they are continuously monitored and that findings are fed back. It also places particularly high requirements on production systems – the more specialised and complex they are, the more difficult it usually is to adapt them.

The first generation of lean production building kit systems responded to these specifications with simple system solutions that could be applied without the need for centralised planning. They made it possible for staff to build additional tools and factory equipment on site. However, when put into widespread use, a number of weaknesses in these systems began to emerge, such as the fact that structures often had to be completely rebuilt just to make minor modifications at the intersection points of tubes. When a component encompasses a tube by more than 180° to create a fastening, it is impossible to fit additional components at the same section of tube.

The next generation of lean production building kit systems is compatible with continuous modification at all stages in the production process. These systems are based on a small number of basic elements that can be repeatedly recombined and added at any point with exceptional flexibility. Additional struts can also be added to strengthen a structure and can be fitted at any angle. Furthermore, the forgiving design principle provides additional support by compensating for tolerances in the lengths of profiles and tubes.

4. Summary

State-of-the-art lean production building kits have been optimised for continuous improvement in the workplace. They use system solutions to create tools and factory equipment without requiring major planning input or material usage. The new generation combines maximum stability with minimum planning and assembly work, thereby ensuring users can build and improve frames on site with no need for complex drawings. As a result, these systems embody the principles of lean production, which strive for flexibility, economical use of resources and maximum quality.

All this is made possible by intelligent fastening technology that guarantees exceptional durability. Cutting-edge fasteners do not need to be retightened and exhibit no settlement, because solutions from state-of-the-art building kit systems are usually based on aluminium tubes and fasteners that ensure optimum strength, unlike systems featuring plastic coatings.

To avoid the complex intersection points that previously had to be implemented with specialised fasteners, modern solutions prefer to use a single type of fastener for all needs. Individual struts can be fitted to intersection points with inherent stability and can even be subsequently repositioned, which makes it easier to adapt existing constructions so that, for example, the incline of a roller conveyor can be modified at a later point in time.

Lean production building kit systems make it possible for staff to build transport trolleys, shelving units, racks, conveyor lines and other factory equipment on site, as their needs dictate. These building kit systems are also ideally suited to needs-based material picking and supply.