Constructing improvement plan for inputs through dialogue with DM about DEA-Efficiency for DMUs

Evaluation of efficiency of the DMUs (Decision Making Units) in a company is a very important problem. Thus, the studies of evaluation of efficiency are being actively carried out on the basis of the production functions, for example Cobb-Douglas production function and fuzzy loglinear production function (fuzzy Cobb-Douglas model). Recently, DEA (Data Envelopment Analysis) was applied to evaluation of efficiency, in the sense of benchmarking evaluation. After having evaluated DMUs by DEA, we obtain the improvement plan for every input in the inefficient DMUs. Though we many not be able to decrease inputs at one time according to the DEA plan, it is natural to construct some phased improvement plans for decreasing the inputs. First, we propose to support the construction of some phased improvement plans by the sensitivity analysis for the evaluated efficiency by applicatiion of definite limits to the decrease of inputs. Second, we evaluate this method by applying it to the case of bank data.