Why lean thinking is returning to UK construction

The principles that underpin lean manufacturing are returning to the UK construction industry. Glass Times talks to Bohle’s Dave Broxton.

The term ‘lean manufacturing’ is coming back into the construction industry’s consciousness, thanks to a drive to promote off-site manufacture.

The UK construction industry first turned to successful Japanese manufacturing techniques in the late 1990s in a bid to cut waste, improve production times, and lower costs. This resulted in Sir John Egan promoting ‘lean thinking’ in his influential report ‘Rethinking Construction’.

Twenty years later and ‘lean thinking is again making a return, this time in relation to off-site construction and the part it has to play in addressing the UK’s housing crisis. This includes centre stage a recent report to the Science and Technology Select Committee.

Dr Robert Hairstans, Edinburgh Napier University, reporting to the committee, said: “Undertaking activities in a factory production flow process as opposed to an on-site framework of disjointed activities facilitates the use of lean techniques.

“The principles of Lean are teamwork, robust communication, and efficient use of resources and elimination of waste. Industrialised building systems therefore have an additional emphasis on improved productivity, quality and safety.”

These are principles, which are according to Bohle’s Dave Broxton, being applied in the glass processing sector, less the accompanying doctrine.

“While I have met people who are committed disciples of lean manufacturing and lean thinking, there are many who just take useful elements from this business philosophy,” he said.

“If you are setting up a car manufacturing firm to rival Toyota, then this approach probably wouldn’t work but for the rest of us, picking out ideas that can make manufacturing or supply processes run more smoothly, is about maximising efficiencies and with them margins. And in this climate, that’s important.”

According to Bohle, glass processors have been squeezed from all sides in recent years, which has started to eat into profits. For example: raw material prices have gone up; labour costs have increased; and the prices customers are prepared to pay have fallen, which has been exacerbated by over-supply.

“The pressures on glass processing companies are immense,” Dave said. “And it is understandable that they are prepared to pay for the latest machinery that will cut labour cost, speed up production and reduce manufacturing errors.

“However, you don’t have to fork out £hundreds-of-thousands on the latest cutting or toughening equipment to make a difference to your bottom line.”

He points to the Japanese concept of 5S, which is a framework of ideas that was originally established to facilitate ‘just in time’ manufacturing (which has arguably become a default setting for the glass and glazing industry).

One of the Ss in the 5S approach is ‘Seiso’, or ‘Shine’, which involves sweeping or cleaning and inspecting the workplace, tools and machinery on a regular basis.

Seiso aims to improve the production process, efficiency and safety, by reducing waste, and preventing errors. To meet this goal, the workplace and equipment must be kept clean, and it must be regularly inspected.

In a glass processing company, Dave argues that time lost in downtime, machinery cleaning, cleaning of water tanks and the costs of wastewater disposal contaminated with glass particles in glass processing can run into £thousands each year, which can be significantly reduced with a sedimentor.

“Sedimentors may not be as sexy as a water jet cutter or an auto loading cutting table, but their role in upholding some of the principles behind lean manufacturing cannot be understated,” he said.

“Research that we carried out found that glass processors can cut the costs associated with cooling and machinery cleaning by almost 10% through the addition of a sedimentor to their processing line.

“If you add in the impact contaminated water can have on product quality, any reduction of what are individually, often unseen overheads, can have a significant impact on your profitability.

“And sedimentors really are an investment; since they help to trim 10% off those costs, the purchase price can be paid back within the year.”

Suitable for elementary to chain-linked, double-sided straight line edgers, Bohle manufactures and supplies three different sedimentors: the 2.4, which has a filling quantity of 2,100 litres; the 1.0, (1,000 litres); and the 0.3, which has a filling capacity of 320 litres.

The fully automated system uses a sophisticated multi-stage process to pump water, first into a settling tank, removing around 70% of heavier glass particles from coolant.

Powdered flocculant is added, and mixed using a programme of currents, which then bonds to the remaining glass particles, making them sink.

At the end of the cleaning process, a valve at the floor of the tank opens and the accumulated sludge is flushed into a filter bag by the water pressure. This leaves the cleaned cooling water ready to be returned back into the cooling circuit.

“Just by reducing the wear and tear on the glass cutting machinery, which will result in less downtime, means that companies that invest in one are already implementing modern manufacturing methods,” Dave said.

“In fact, the sedimentor sits at the heart of the lean manufacturing philosophy: to reduce waste in order to improve production time and lower costs.”

Bohle’s research also shows that clean cooling water increases the performance of machinery by up to 20% and the service life of tools by up to 30%, delivering additional through-life savings.

Since tools last longer, waste is reduced. Similarly, man-hours are not wasted changing them, and production time is improved. And the cost of production is lowered as a result of both of these savings.

“Adopting lean manufacturing principles to your workplace is fundamental to delivering a healthier bottom line,” Dave said. “There is no better place to start than by ensuring your machinery runs efficiently and continuously by thoroughly cleaning your cooling water.”