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Research [Industrial Engineer]
[October 14, 2014]

Research [Industrial Engineer]

(Industrial Engineer Via Acquire Media NewsEdge) This month we highlight two articles that focus on using operations research to cost-effectively improve the reliability and safety of service systems. The frst article develops an improved policy for screening blood donations to reduce the transmission of infectious diseases. The second article addresses determining the number of reserve drivers needed in an urban bus system to ensure service. These articles will appear in the November 2014 issue of IIE Transactions (Volume 46, No. 11).

Operations research makes for safer blood products Blood products (whole blood, red blood cells, plasma, platelets, etc.) are essential in many modern medical procedures, including organ transplants and other major surgeries, and treatments of cancer patients, trauma victims, premature infants, severely anemic children and pregnant women with complications. Between 40 percent to 70 percent of the U.S. population will need a blood transfusion at some point in their lives.

Unfortunately transfusions come with a small risk of transfusion-transmitted infections (TTIs). For example, HIV, hepatitis viruses, human T-cell lymphotropic virus, syphilis, West Nile virus (WNV), dengue viruses (DENV) and the babesia parasite all can be transmitted through blood products.

To minimize the risk of an infection, the blood supply in the U.S. and other advanced nations is screened rigorously. In the U.S., the Federal Drug Administration (FDA) provides a list of TTIs for which donated blood must be screened and approves screening tests. Each TTI can have multiple FDA-licensed tests, each with a different cost and efficacy. Given that the FDA may not mandate a specific test set, blood centers must establish a testing strategy, including test selection from the available alternatives, under a limited budget. (Testing cost is a major component of the cost of blood in the U.S.) Several characteristics complicate the decision to select tests. If transmitted, health consequences of some agents greatly depend on patient level factors. For example, West Nile virus and babesia infections are more likely to exhibit severe consequences in patients with weakened immune systems. Further, prevalence rates in the donor population can vary across the U.S. For example, babesia is endemic only in certain Northeast and Upper Midwest states. A customized, nonuniversal screening scheme that considers the important characteristics of transmission and prevalence can be very effective for reducing the TTI risk.

Developing such a scheme is the problem studied by doctoral student Ryan Xie and professors Doug Bish and Ebru Bish from Virginia Tech and Dr. Susan Stramer from the American Red Cross in their article, "Going Beyond 'Same-For-All' Testing of Infectious Agents in Donated Blood." In case studies using real data, their optimization model is shown to produce testing schemes that outperform universal testing schemes that follow FDA guidelines. This work, which is part of a broader National Science Foundation project, has important implications on public policy.

CONTACT: Douglas R. Bish; drb1@; (540) 231-0462; associate professor, Grado Department of Industrial and Systems Engineering, Virginia Tech, Blacksburg, VA How many reserve drivers does a bus system need? How do transit agencies in large metropolitan areas manage to operate thousands of buses on fixed routes and deliver reliable service according to published timetables? The answer lies, in part, in their use of extraboard (or reserve) drivers. Extraboard drivers cover open work that arises from planned or unplanned events, such as vacations, sick leaves, bus breakdowns, weather emergencies, traffic disruptions and special events.

Reliable service comes at a price - the size of an extraboard workforce including vacation coverage can be as high as 26 percent of the total workforce, but extraboard drivers' utilization is only about 50 percent to 60 percent. In contrast, regular-duty drivers' utilization is close to 100 percent. Still, transit agencies spend tens of thousands of dollars each day on overtime pay to cover open work.

In their paper titled "The Extraboard Operator Scheduling and Work Assignment Problem," Fei Li and Professor Diwakar Gupta of the University of Minnesota's industrial and systems engineering department investigate smart work assignment and driver scheduling algorithms that have the potential to assign more work to extraboard drivers, thereby lowering overtime cost.

Li and Gupta model a dispatcher's decision problem at a point in time at which some pieces of work are known and drivers' shiftstart times are not fixed. A key feature of their model is that it considers both spread time and work time constraints; for example, drivers may have a 12-hour shiftbut may not be assigned more than eight hours of work without incurring overtime charges. This problem is a combinatorial optimization problem belonging to the class of NP-hard problems.

Li and Gupta propose and compare different heuristics and recommend a decomposition-based approach that runs in polynomial time and guarantees that even in the worst case its solution will lie between 63 percent and 70 percent of the best possible solution.

By applying their algorithm to data from Metro Transit, the agency responsible for the bulk of transit services in the Twin Cities of Minneapolis and Saint Paul, Minnesota, the authors show that their approach could save transit agencies thousands of dollars in overtime costs each day.

CONTACT: Fei Li; lixxx768@umn. edu; Diwakar Gupta;; Department of Industrial and Systems Engineering, 111 Church St. SE, University of Minnesota, Minneapolis, MN 55455 The most recent issue of IIE Transactions on Healthcare Systems Engineering (Volume 4, Issue 3) contains four articles covering a wide range of healthcare system problems and solution methods. Brief summaries of two of the articles are given below. The frst summary discusses the potential positive benefts and return on investment of using RFID technology to manage assets in a healthcare setting. The second discusses a joint effort between academics and healthcare professionals to understand the key factors needed to make an innovative care coordination approach to surgery successful.

I need a ventilator for my patient - stat! Asset management of medical equipment is a large contributor to healthcare costs not only in loss of equipment like IV poles and wheelchairs that literally roll out the door, but also in time and effort spent searching for misplaced assets. An example of this is a ventilator that leaves the emergency department with an admitted patient, so that the ventilator is not available to the next patient who arrives in the emergency department.

One way to track equipment location continuously is radio frequency identification (RFID). RFID can be expensive, but costs are coming down due to better technology and wider adoption, which helps lead to an economy of scale. The overall goal of the research in "Asset Management in Healthcare: Evaluation of RFID" by Justin Rousek, Kalyan Pasupathy, David Gannon and Susan Hallbeck was to determine the return on investment (ROI) and payback period for a new RFID system based primarily on search time, shrinkage (loss) and better utilization of common equipment (assets) in a hospital system.

Surveys were used to identify asset search times for clinicians and maintenance, along with inventory times for biomedical staff. The calculated reduction of time spent searching by 50 percent, of reducing shrinkage by 50 percent and increasing utilization by 10 percent were compared to the RFID implementation, maintenance and RFID tag costs using ROI. The ROI was 327 percent with a payback period of less than one year.

The results of this project were used to make the case for RFID technology for a Midwest tertiary care hospital system. The methodology used in this project will be used to quantify the ROI for an RFID system that is being integrated into a new emergency department renovation at another Midwest tertiary care hospital. That RFID system will track assets in addition to patients and providers, yielding a wealth of information for future industrial engineering modeling efforts for ROI as well as studying communication networks, teamwork and streamlining patient flow.

Leveraging collaboration between clinicians and industrial and systems engineers and using advanced analytics will help create the emergency department of the future.

CONTACT: Kalyan Pasupathy;; (507) 284-2511; Mayo Clinic, 200 First St. S.W., Rochester, MN 55905 Systems engineering helps assess more patients Systems integration and coordination are becoming increasingly important in healthcare systems around the world, particularly with the new healthcare policy and reimbursement paradigms in the U.S.

Outpatient surgery is an example of the need to coordinate for optimal patient outcomes. Such surgeries demand that surgeons, anesthesiologists and other providers cooperate to meet the varied needs of patients. Historically, these services have been fragmented, with minimal coordination between providers.

Building on the surgical home concept proposed by the American Society of Anesthesiologists, University of Texas, Austin researchers Douglas Morrice, Jonathan Bard and Dongyang (Ester) Wang, along with Luci Leykum, Susan Noorily and Poornachand Veerapaneni from the University of Texas Health Science Center at San Antonio, describe the development and implementation of a patient-centered surgical home at University Health System, the health science center's primary teaching affiliate. Their findings are published in "A Patient-Centered Surgical Home to Improve Outpatient Surgical Processes of Care and Outcomes." At the heart of the patient-centered surgical home is an anesthesia preoperative clinic (APC) designed to coordinate care and assess all patients prior to surgery. Using simulation and statistical analysis of observational and historical data, the researchers show that for the patientcentered surgical home to be successful, the anesthesia preoperative clinic must see the right patients with the right information by overcoming improper triaging of patients and patient information deficiencies.

In addition, having enough capacity at the anesthesia preoperative clinic to assess all patients is crucial. Hence, this research demonstrates that with a proper patient information gathering tool and modifications to the way patient triage is handled, it is possible to increase by a significant number the patients the anesthesia clinic sees each day with only a modest increase in resources. In fact, results from a designed experiment indicate that proper triage coupled with improved information leads to reinforcing improvements on patient times in the anesthesia clinic.

The potential is great. In addition to improving patient care, the University Health System could save an estimated $1 million with better operating room utilization and decreasing unnecessary patient testing. Since APC-like clinics are common, the research findings could be applied on a wider scale.

CONTACT: Douglas Morrice; douglas.; (512) 471-7857; Red McCombs School of Business, The University of Texas at Austin, 2110 Speedway Stop B6500, Austin, TX 78712-1750 About the journals IIE Transactions is IIE's fagship research journal and is published monthly. It aims to foster exchange among researchers and practitioners in the industrial engineering community by publishing papers that are grounded in science and mathematics and motivated by engineering applications.

IIE Transactions on Healthcare Systems Engineering is a quarterly, refereed journal that publishes papers about the application of industrial engineering tools and techniques to healthcare systems.

To subscribe, call (800) 494-0460 or (770) 449-0460.

Ronald Askin is a professor and director of the School of Computing, Informatics and Decision Systems Engineering at Arizona State University. He is editor-in-chief of IIE Transactions and a fellow of IIE.

John W. Fowler is the Motorola Professor and Chair of the Department of Supply Chain Management in the W.P. Carey School of Business and a professor of industrial engineering at Arizona State University. He is editor-in-chief of IIE Transactions on Healthcare Systems Engineering.

(c) 2014 Institute of Industrial Engineers-Publisher

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