A synthesis process to arrange the eligibility conditions for the structural decentralised discrete-event systems

In the supervisor control theory framework of discrete-event systems, modular or decentralised control schemes are proposed and used to overcome computational complexity problem. However in most studies, the eligibility conditions to establish those schemes are required to be verified for every specification. This means that even a minor modification of specifications such as production sequences or material mixing rates, the whole decentralised control needs to be verified again for the eligibility conditions. The structural decentralised supervisor control scheme [3] tried to overcome this issue by establishing the conditions in the structure of the system rather than the specification itself. Hence once the given structure of the system is verified, then a set of future decentralised controls would guarantee the centralised optimal supervision. It has shown that this would bring an exponential computational savings. In this paper, as a natural extension, we propose a way to modify the structure of decentralised discrete-event system such that the resultant system could possess such desired structural properties. The synthesis process needs to be done in certain points when the major changes to the plants are introduced, and once established, a number of variations in their specifications can be implemented without further computationally expensive verification. Hence even though the process is seemed to be complicated, in the long run, it will save the huge computational burden. This paper presents a process to arrange such conditions for the given structure of the system and demonstrate it with examples.