System improvement can be used to increase productivity and solve problems in official activities. For the best outcome, the improvement must have a scientific and systematic base. The system elements blend together for collective goals. They interact with each other to realize a special aim. System improvement consists of the analysis of the following: the work flow-chart, place use, official objects use, the form used for official activities, staff use, official materials use, time use, and costs. In order to solve system problems or to improve the system, the managers or the system analyzers use simplifications and/or idealizations in the problem, and/or in analyzing the inputs and outputs of the system. A suitable communication is another important issue for productivity. For a harmony between buildings with a long use life and for modular organizations, a flexible architectural planning is needed. Thus, the design should not prevent rational work conditions and should satisfy the changeable needs of the office. A model to improve the management buildings used by private work sector is therefore proposed in this study. The model is beneficial for the designer in clearly indicating which steps have to be followed in such designs. The model can be used as a program or a checklist for designing the management buildings in the private work sector. It is hoped that this model will serve as an easy guide for designers.