The authors have analysed and evaluated a two-dimensional instruction set of parallel operation based on optical array logic (OAL), which is a digital optical computing paradigm, to clarify efficient composition of an optical computing system based on OAL. To evaluate parallel operation based on OAL, the author have introduced new indices and evaluated a logical instruction set of various parallel operations with the indices, so that a guideline for composing a simple and efficient OAL computing system is clarified. Also, the authors have proposed the reduced operation kernel set correlation technique to perform parallel operations more efficiently by a simple OAL computing system. It has been clarified that the technique can reduce the required hardware necessary for an OAL computing system for efficient general-purpose processing.