Research Reports from the Department of Operations
Document Type
Dissertation
Publication Date
1-1-1983
Abstract
Inventory systems in a health care setting include a multitude of items that are finitely reusable. Examples of such items are linen, glassware, silverware, patient gowns, towels, and, in general, all surgical implements that can be sterilized. Because the economic life of such items is rather long, they represent an investment which cannot be used elsewhere. In addition, the processing of these items might be very costly due to the required investment in the processing equipment and its maintenance, the labor and energy costs, and the high interest cost. As these costs have skyrocketed during the '70s, the cost of owning and using the reusable items has also increased. As a result, several hospital material managers began looking for ways to maintain a minimal overall cost. The lack of mathematical models dealing with real-life problems similar to the reusable item in the hospital environment requires a new approach. Basically, the new approach relies on the concept of systems analysis. First, the system is studied thoroughly, then the desires of the users involved are analyzed to find a model that will best represent the problem at hand. The first phase is broken into stages: A study of the demand pattern in each department allowing for different possible scenarios such as a fully deterministic department population, a fully deterministic department population with probabilistic needs for the items, a demand process generated by a Poisson population, a deterministic population, and, last, a fully probabilistic department population. To completely understand the inner mechanisms of the system, such as the interdepartment exchange of items, grouping the departments homogeneously--within which the departments are free to borrow and loan items to other departments in the same group--is permitted. The distribution process is also analyzed and formulated so that items can be distributed either separately, in trays or both ways. The objective of this work is to find an optimal policy that maintains the service level for the different reusable items, higher or equal to some fraction specified by management. By optimal policy it is meant a policy that: (1) Minimizes the total expected cost of owning, holding and processing the items, as well as the review cost. (2) The interprocessing cycle as well as the interreview cycle should be within the specified ranges. The models assume that the population level in each user department is stationary. The models developed in this thesis have been applied to the case of Marymount Hospital in Garfield Heights, Ohio. The results are impressive since the models suggest a reduction of the inventory level by almost a factor of two.
Keywords
Operations research, Medical instruments and apparatus, Inventory control--Mathematical models, Hospitals--Materials management, System analysis--Case studies
Publication Title
Dissertation/Technical Memorandums from the Department of Operations, School of Management, Case Western Reserve University
Issue
Technical memorandum no. 518
Rights
This work is in the public domain and may be freely downloaded for personal or academic use
Recommended Citation
Boukaabar, Boudjelal, "A Multi-Item Multi-component Two Echelon Model for Reusable Items in a Health Care Setting" (1983). Research Reports from the Department of Operations. 321.
https://commons.case.edu/wsom-ops-reports/321