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Two recent CHOIR publications now online

Recently, two new CHOIR papers have been published. A review article on laboratory performance indicators by Eline R. Tsai, Andrei N. Tintu, Derya Demirtas, Richard J. Boucherie, Robert de Jonge and Yolanda B. de Rijke. Furthermore, Maarten Otten, Aleida Braaksma and Richard Boucherie published a paper on Minimizing Earliness Tardiness costs on multiple machines with an application to surgery scheduling.

The abstract are below.

A critical review of laboratory performance indicators 

Healthcare budgets worldwide are under constant pressure to reduce costs while improving efficiency and quality. This phenomenon is also visible in clinical laboratories. Efficiency gains can be achieved by reducing the error rate and by improving the laboratory’s layout and logistics. Performance indicators (PIs) play a crucial role in this process as they allow for performance assessment. This review aids in the process for selecting laboratory PIs—which is not trivial—by providing an overview of frequently used PIs in the literature that can also be used in clinical laboratories. We conducted a systematic review of the laboratory medicine literature on PIs. As the testing process in clinical laboratories can be viewed as a production process, we also reviewed the production processes literature on PIs. The reviewed literature relates to the design, optimization or performance assessment of such processes. The most frequently cited PIs relate to pre-analytical errors, timeliness, resource utilization, cost, and the amount of congestion. Their citation frequency in the literature is used as a proxy for their importance. PIs are discussed in terms of their definition, measurability and impact. The use of suitable PIs is crucial in production processes, including clinical laboratories. By also reviewing the production processes literature, additional relevant PIs for clinical laboratories were found. The PIs in the laboratory medicine literature mostly relate to laboratory errors, while the PIs in the production processes literature relate to the amount of congestion in the process.

Minimizing Earliness/Tardiness costs on multiple machines with an application to surgery scheduling

Early or tardy surgeries are frustrating for both patients and personnel, and cause inefficient use of resources at the operating rooms. The stochastic Earliness/Tardiness (E/T) scheduling problem addresses this by minimizing the total expected deviation of the surgery completion times from the planned completion times. We introduce the concept of E/T-concavity as a property of a probability distribution if the E/T costs are concave as a function of the standard deviation of the completion time, whenever the optimal planned completion times are selected. We use this concept to generate an optimal schedule for the multiple machine variant of the E/T problem. The optimal schedule is not unique and therefore allows us to consider several optimization objectives in addition to the E/T objective. We demonstrate the usefulness of our results in practice by proving E/T-concavity for several probability distributions and by showing that, under the assumption of E/T-concavity, a simple Shortest Variance First (SVF) rule is optimal. We conclude by providing a numerical example of surgery scheduling where we demonstrate the benefits of the SVF rule compared to several commonly used scheduling rules.