Standard practice is better

Without at any point trying to exaggerate, Ronald Does immediately makes it clear where he stands. 'The doctor who says that every patient is unique is oversimplifying things. Such an attitude can lead to an enormous variation in treatment, but in many cases a standardized approach based on best practice is preferable. Variation in processes will ultimately hurt the customer.'

Does takes the example of the way in which hospitals deal with patients who need to have a new hip. 'At the end of the last century, patients used to stay in hospital for at least 2 weeks after hip surgery. Since then, the length of hospital stay has been reduced to 1 day by applying improvements resulting from projects with multidisciplinary teams including nurses, physiotherapists, statisticians, anaesthetists and orthopaedists. Improvements were made by new practices in the area of pain management and by adjusting the logistical cooperation between the teams. We used statistics to show that it was precisely on these points that efficiency gains could be made.'

Fewer errors and satisfied customers

Does states that 'a doctor should, of course, treat every patient as an individual and make the correct diagnosis. But once the diagnosis is made, rather than proceeding by giving a tailor-made treatment, it is better to apply the proven treatment method.' According to Does, standardising the treatment process on the basis of the best available methods reduces the number of systematic and unnecessary errors and will ultimately result in the highest levels of customer satisfaction. During the adjustment of the process, however, the whole picture must always be taken into account. If, for example, an accelerated treatment leads to more complications, something is apparently not right. It is the total output that needs to be evaluated.

Does is Professor of Industrial Statistics at the Amsterdam Business School (ABS) and founder and director of the Institute for Business and Industrial Statistics (IBIS UvA), which celebrates its 25th anniversary this year. Under Does's leadership, IBIS implemented process improvements at Dutch companies such as ABN Amro, Aegon, DAF trucks, Heijmans and Wolters Kluwer and at various hospitals. The institute works on the basis of Lean Six Sigma, a statistical method for improving business processes.

People are not machines

Hospitals have Does’s special attention: 'In a sense, it is easier to optimise industrial processes than medical processes as medical processes are largely determined and influenced by humans.' IBIS was active at hospitals including UMC Groningen and the Red Cross Hospital in Beverwijk, both in the Netherlands. Based on Lean Six Sigma, the institute worked to reduce the length of hospital stay, reduce post-operative wound infections and unnecessary diagnostics and improve purchasing processes in thirteen hospitals.

Precisely because of the paramount importance of the human factor, Does believes that there is still much to be gained in medical processes: 'The number of wound infections that occur after surgery is enormous. Percentages of between 10 and 20 are not uncommon. An important cause is that the door of the operating theatre is constantly being opened and closed, which causes differences in atmospheric pressure.' According to Does, it is possible to reduce the occurrence of wound infections considerably, but he estimates that it will be difficult to reduce the rate of wound infections to less than five percent: 'A percentage of 0 would be optimal, but people are not machines. In mechanical processes, it’s not unusual to try to reduce the error rate from 120 to 20 per million.'

Lean Six Sigma

Does indicates that the human factor is also the reason why we should not exaggerate the ultimate effect of methods such as Lean Six Sigma. 'It is frustrating that the number of organisations that have experienced the full benefits of our method over an extended period of time is limited', says Does. The core of the Lean Six Sigma methodology is that it identifies, on the basis of statistical methods, the processes that show unnecessarily large variation. Its solutions are partly based on practices that have been proven to work well, what are referred to as 'best practices'.

​Implementation is crucial

An remarkable detail of Lean Six Sigma is that process optimisation within the organisation is implemented by the employees themselves. Through training at IBIS, employees receive, depending on their role in the improvement process, a certification such as 'Black Belt' and 'Green Belt'. 'We teach employees to improve processes by looking at them in a different way', says Does. 'Thousands of projects have achieved immediate short-term results. The trick, however, is to stick to the new way of working. New ways of working disintegrate for all sorts of reasons.' Doctors, for example, rarely take part in the courses, which means that there is a lack of support. A newly appointed board may want things to be done differently. 'Statistics remain at the heart of our method. Unfortunately, few companies can say that its implementation has been perfect. You can lead a horse to water, but you can’t make it drink.'

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