Researchers at the front line TIME IS MONEY as the saying goes, and no one knows that better than the man who has spent most of his professional life trying to conserve it. Not that he's been against the clock. For Edwin Cheng Tai-chiu, chair professor in Polytechnic University's department of management, has been saving vital minutes for more than 20 years. 'Time is a precious resource,' said Professor Cheng, whose specialist skill is scheduling - the art of doing things efficiently. The results of his research, which won him a senior reserarch fellowship from the Croucher Foundation in 2001, have been applied both locally and overseas in fields ranging from food production to pharmacology and astrophysics. The former PolyU vice-president's work reportedly helped a New Zealand food production company achieve a 30 per cent saving in operating costs. 'This was quoted in the literature. I was very excited about it.' The latest interest has come from a Taiwanese film company trying to find the most cost-effective way of organising stars on movie sets. 'You have talent waiting on the set, but sometimes not required in all scenes. So the problem is how to sequence them so that idle time is minimised. It is one of the scheduling problems we studied and came away with a solution for. 'Scheduling and logistics are about optimal planning of resources. All human endeavours involve talking about planning all the time. If you are innovative enough, people can use your models in different contexts,' he said, citing studies in the US to schedule court cases. Professor Cheng has tackled long-standing problems of theoretical scheduling research that have baffled scientists for decades, including one which he proved to be insoluble, sparing the need of his counterparts to devote any more time to it. The usual approach to tackling scheduling problems was to turn them into mathematical models, which often provided a challenge. An industrial engineer by training, Professor Cheng has also undertaken empirical research into management. It was during his doctoral studies at Cambridge University that he 'stumbled upon' scheduling science, which became the topic of his PhD thesis. He said he preferred 'the softer side' of engineering to traditional system design, opting instead to study planning and logistics. Professor Cheng has been a consultant on the allocation of resources for many years now and his research team has recently come up with a method of evaluating the performance of a supply chain in transport logistics and has sought a US patent for it. His postgraduate education in Britain helped him to become an independent learner, he said, and he had developed his ideas through self study over the years, going on to teach business courses in Canada and at Chinese University of Hong Kong before joining PolyU in 1992. 'My school days in Hong Kong gave me one good thing, however, and that's rote learning. I got a very good training in how to memorise things. A good memory is a plus for all kinds of research. You need to recall things all the time,' he said. Professor Cheng said he tried to encourage his students to embrace life-long learning, increasingly important in today's competitive society. 'We should broaden students' horizons by requiring them to have more interests, not just focusing on one or two areas,' he said. 'Hong Kong students are rather narrow, partly because of the fact they do not spend enough time reading newspapers, for example. They spend time on things not related to enriching their knowledge.' He said he tried to motivate students by introducing real life problems to class. When teaching inventory management, for example, he tended to relate it to everyday decisions such as how much cash to keep in their pockets. 'If you have too much you lose interest, if you have too few bank notes, you may run short. Then there is the cost of getting the money from the bank or machine: there may be a long queue,' he said. Professor Cheng gave other examples of the importance of scheduling. 'It makes a big difference,' he said. 'Just imagine a courier service, with companies using strategies to plan their flights. Oil prices are high these days, so going shorter distances saves a lot of money. They can plan routes so they travel the shortest distance. 'Another operational issue is how many aircraft you need to deploy and how to pack the products into them. You can simply stack them in any order but you may then need to use extra aircraft. But if you do it in an optimal way you might reduce the number of planes you need, cost-saving again.' Although excited by his research, Professor Cheng said it was teaching that gave him the greatest satisfaction and that was the main reason he stepped down as PolyU vice-president in 2000 after five years to concentrate on teaching and research. 'Research also gives me a lot of satisfaction, but it limits me to my own self-advancement or recognition by my peers. It is less influential than educating students. I have been teaching up to 150 students and that has a much wider influence than research.'