TPS Interviews-2: Prof. Dr. M. Bülent Durmuşoğlu

M. Bulent Durmusoglu has been worked as professor in Industrial Engineering Department at Istanbul Technical University(ITU). He has had more than 40 years university experience and more than 30 years industry project experience. He completed his doctorate in the ITU Industrial Engineering Department in 1986. Doctorate topic is relevant with “Design of Group Technology Cells”. Mr. Durmusoglu has started to think about lean transformation in Turkey without naming it since those years although there was no expression of lean thinking in those years. He prepared 4 sub-projects of a well-attended 12 projects about “Multi-dimensional Strategy Determination and Development Master Plan” for Pancar Motor Inc. in 1989. He has contributed to the many SMEs and big scale companies on lean transformation projects as project advisor since those years. He can say that 3 companies has transformed to lean totally. These companies still continue to lean studies and improve themselves continuously. Besides, he has helped for training lean experts through giving many practical trainings for industry.

He teaches “Integrated Production Systems” and “Group Technology and Flexible Production Systems” in the undergraduate program, “Lean Production and Management” in the postgraduate program, and “Modelling and Designing of Production Systems” in the doctorate program. He coordinates also 84 hours “Lean Production and Management Certificate Program” in the ITU Continuing Education Center. He trained 14 doctorate students. Some of them study in the industry and some of them study at universities as associate professor and professor. He has more than 40 publications in the reputable international journals and book episodes. Mr. Durmusoglu has a book about lean transformation(No other languages translation yet).

1) There are many implementation tools under lean manufacturing title. 5S, kanban, standardization, just in time, value stream mapping, A3 report, root cause analysis, hoshin kanri system, SMED, TPM, asakai, oobeya etc. What is the most important or most primary tool for you after 30 years industry experience?

Tools should be chosen and taken implementation according to one change in one time rule. The most primary tool is cellular manufacturing which is not referred above for me. It is the most primary tool of creating flow.

2) You referred that stock reduction visualise the problems at factories in your book. Do you implement regular stock reduction activities in the companies that you work as advisor? If you implement, what method do you follow?

We control the stock quantities with cellular manufacturing and Kanban system, and after we study to reduce quantities with Kaizens.

3) There is “There is no doubt that the competition for the future will not be between companies but between supply chains.” expression in your book also. I think also that this is inevitable and it is late for this topic. As Henry Ford explains in his book Today and Tomorrow, the final point he has reached in his efforts to improve total lead time is as follows: In 1926, the lead time was 81 hours from extracting iron ore to getting a car of more than 5000 parts, complete and ready for shipment, on the train. There isn’t still a company that can be achieved such a lead time in the automobile sector after 96 years.

Why don’t large-scale manufacturers pay enough attention to total lead time in this period when the term of “speed” almost precedes the term of “quality”? What do you think?

The product variety has increased tremendously in many companies and the companies cannot be shorten the lead times due to muri and mura. In addition, business owners listen to the word of cost accountants before the lead time in the traditional systems.

Meanwhile, suppliers in sectors other than automotive carry out traditional production under extremely primitive conditions. This is one of the most important reasons for the increase in lead times.

4) Eliyahu Goldratt says that TPS has limits and demands stability on three issues in his article Standing on the Shoulders of Giants at the end of his The Goal book,

• Processes and products must not change significantly for a long time.

• The demand for a product must be stable.

• The total load of orders must be stable for different sources.

If even one of these three stability is not available, the tools of TPS can be used; but he says not to expect a great success like Toyota. You worked as advisor in many different companies. Do you think lean manufacturing demands stability in these three issues? Is lean manufacturing not fully applicable everywhere?

It is a good question. There are solutions for demand fluctuation(mura). However, overloading above the capacity(muri) generally disrupts the established systems. Overloads can be shifted to the sub-contractors. This can cause quality problems and exponential growth of lead times. Muri can only be overcome with the sales departments of the companies that have a principled stance. In conclusion, Goldratt’s determinations are right. In addition, the problem of employees’ inability to maintain their behaviours according to lean principles is also very important. The old habits of people and high turnover rate in companies cause the problem of sustainability. If we collect all the reasons, it is generally not possible to operate lean systems exactly like the Toyota Production System.

5) Does lean manufacturing have a future? It was something that I thought a lot about as I was creating my career towards the end of my student life. Many of my friends have shifted towards the “Big Data” field that very popular now. How long will lean production remain popular in this period when Industry 4.0 is spoken? I still remember a ladder diagram drawn by Prof. Dr. Emre Çevikcan in class. The lean production should be applied before the automation and Industry 4.0. The system should be purified from wastes and automation should be established above this lean system. In this context, I also think that lean production will never lose its popularity and it will be much more important in the future, in periods when large investments such as the dark factory become widespread, as it will reduce the initial investment. What do you think about it? I also want to ask for students and colleagues who want to shift lean manufacturing and have question marks in their minds. Do you think lean manufacturing has a future?

I think that it will not be possible for a company that cannot be lean to digitize and moving to industry 4.0. However, the company can be established as Industry 4.0 from scratch. However, there should still be lean processes in it. It is a very shallow way of thinking to realize Industry 4.0 with thoughts such as let’s spend money, let’s have a dark factory. It’s easy to spend money, but it’s different to realize much with less through using your mind. 

6) I am very happy to had the chance to work with you for two years at the university. I know how much you have internalized lean production and this internalization is an inspiration to both your advisees and your students. Can you give some examples that you apply lean production in your personal life outside of work for setting an example also for readers?

I pay attention to timing so much. I have never been late to class or training. I find any information or slide in maximum 25 seconds. I spend a lot of time for this, but I never feel sorry for this time. It gives me a lot in the long run.

Besides, I try to keep a work-life balance. I also consider trying to protect my physical health by doing mental analyzes and sports as a value stream management for myself.

7) There are hundreds of companies that implement or has just started to implement lean production. What advice would you give to improve themselves in the lean production field?

Continuously learning about this subject and knowing what they don’t know is the starting point of lean transformation.

8) What advice would you give to students who want to make career on production sector and in what areas would you recommend that they improve themselves?

My most important advice is to learn factory physics firstly. I would also recommend them to work on behavioural sciences.