The OPSS is an 8 stage program which was developed as a practical tool for occupational health services planning. This paper examines the theoretical aspects of the first two stages. The OPSS is a planning tool with a theoretical grounding in OHP (The practical theory of Occupational Health Planning). The target population setting has two functions. The first is to establish the physician's first-hypothesis to design a program. The other is deciding the group which has an occupational health problem in a company. The Needs Assessment helps to clarify the physician's hypothesis, which may be weak due to the limited knowledge of various demands of the employees and senior management. On the other hand, the risks and needs vary according to what kind of expert looks at a situation. To date, occupational physicians have been limited to their medical background in determining only risks and needs. However, understanding the various stakeholders in a particular environment means that any project will be more relevant to all concerned. Another limitation of the occupational physicians hypothesis can be the lack of objective data to support it. This makes it difficult to persuade senior management to sign on to a program. The Needs Assessment procedure with OHQ steps is useful in a number of ways. The Observation step allows for finding risks and needs from various situations in the company from the occupational physician's viewpoint (prehypothesis setting). Hearing is for understanding the subject's demands and finding common themes in the company (final hypothesis setting). Finally, the questionnaire step is for providing objectivity of these common themes and quantitative data for the next Priority Setting procedure. The BITOP (Budget, Information, Time, Order, key Person) has been proposed as a way to diagnose the structural and functional aspects of an organization's procedures. Budget tracks the financial flow through the organization, while Information identifies key information sources. Time helps to understand the reaction speeds of a company against environmental changes in the business community. Order looks at the flow of information from senior management through strategic gatekeepers. Understanding this flow helps the occupational physician to identify specific issues at various levels of the organization. Finally, key Person looks at the flow of information up through the organization, and identifies which key executives the occupational physician needs cooperation from in order for the project to be approved and successful. The above two procedures are essential tasks for insuring that an occupational physician can effectively implement a project that identifies what is necessary for the company and what the company wants to do, and works effectively within the organizational structure.