On The Computational Complexity Of The Manufacturing Job Shop And Reentrant Flow Line

This paper presents a comparison study of the computational complexity of the general job shop protocol and the ow line protocol in a exible manufacturing system. It is shown that a certain representative problem of nding resource invariants is NP-complete in the case of the job shop, while in the ow line case it admits a closed-form solution. The importance of correctly selecting part ow and job routing protocols in exible manufacturing systems to reduce complexity is thereby conclusively demonstrated.