This dissertation comprises three essays in which we develop optimization, econometric, and simulation models to help traditional retailers improve in-store operations. Our modeling efforts aim to tackle inventory record inaccuracy (IRI) and suboptimal staffing levels, both of which are pervasive problems in retailing and cause non-trivial profit loss. In the first essay, we devise two optimization models that represent current practices in industry to minimize costs induced by IRI: daily-fraction and all-or-none inspection. We further perform a case study to identify deficiencies of store operating practices given different risk preferences. Our findings provide practical guidelines for managers to design cost-efficient inspection policy. In the second essay, we develop a dynamic simulation model to analyze multiple antecedents of IRI. Based on simulation results, we derive two hypotheses on the association between IRI and labor. The panel data analysis shows that both the level and the mix of store labor have strong impacts on IRI. Our analysis derives qualitative insights for retail managers to prevent the occurrence of IRI. Finally, in the third essay, we perform an empirical study to improve staffing decisions in retailing. We first develop a response function to quantify the impact of labor and traffic on sales. Grounded on the function we propose a traffic-based staffing heuristic, which performs closely to the optimal and outperforms existing staffing levels in counterfactual experiments. A major contribution of our study is to quantify the benefits of delivering labor plans based on traffic information. Also, the staffing approach is easy to use and saves the need for traffic forecasting.

<p>In today‟s manufacturing environment, different parts manufactured in-house and bought from suppliers are often assembled together into a finished product. Competition has made it very important for companies to deliver a customized product on a promised date. However, when inventory items are missing at the time of production, lead times for products become uncertain and this makes it difficult to fulfill a customer order on the promised date. It is thus important to explore the causes of missing items at the time of production in order to solve such a problem. This Master of Science thesis carried out through a case study at Fläkt Woods in collaboration with Jönköping University is about the problem of not finding specific inventory items in the locations specified by the computer system. It is delimited to inventory items which are physically within the company premises or which according to the computer system are within the premises of the company. The questions at issue have been what the causes of the problem of missing items within the company are and how to effectively reduce the problem. The thesis has been carried out over an entire academic semester as a full-time work in the company. The sources of the problem have been found to be the result of the work procedure, the underlying software used during work (the in-house developed ERP system), stealing from orders, ineffective barcode scans, re-sequencing at the component manufacturing department (called pre-manufacturing in the company) due to the need to fulfill multiple objectives, set-up times at the component manufacturing department and human errors among others. The suggestions given include: modification of the work procedure and the underlying software used at work, increasing effective scanning and using some checks at critical points in the material flow. Areas for further research are given to further reduce the impact of the problem on the production system.</p>

In today‟s manufacturing environment, different parts manufactured in-house and bought from suppliers are often assembled together into a finished product. Competition has made it very important for companies to deliver a customized product on a promised date. However, when inventory items are missing at the time of production, lead times for products become uncertain and this makes it difficult to fulfill a customer order on the promised date. It is thus important to explore the causes of missing items at the time of production in order to solve such a problem. This Master of Science thesis carried out through a case study at Fläkt Woods in collaboration with Jönköping University is about the problem of not finding specific inventory items in the locations specified by the computer system. It is delimited to inventory items which are physically within the company premises or which according to the computer system are within the premises of the company. The questions at issue have been what the causes of the problem of missing items within the company are and how to effectively reduce the problem. The thesis has been carried out over an entire academic semester as a full-time work in the company. The sources of the problem have been found to be the result of the work procedure, the underlying software used during work (the in-house developed ERP system), stealing from orders, ineffective barcode scans, re-sequencing at the component manufacturing department (called pre-manufacturing in the company) due to the need to fulfill multiple objectives, set-up times at the component manufacturing department and human errors among others. The suggestions given include: modification of the work procedure and the underlying software used at work, increasing effective scanning and using some checks at critical points in the material flow. Areas for further research are given to further reduce the impact of the problem on the production system.

Sammanfattning Kurs: Examensarbete i Logistik för Civilekonomprogrammet, 30 hp, 4FE19E.  Författare: Jakob Bergman och Jim Andersson. Examinator: Peter Berling Handledare: Peter Berling  Medbedömare: Hana Hulthén Titel: Saldoavvikelser i producerande företag, en fallstudie på Getinge Disinfection AB. Bakgrund: En välfungerande lagerhållning är en väsentlig grundsten för ett företags framgångar. I takt med att lagerhållningen blivit mer automatiserad och effektiviserad ställs högre krav på att informationen om lagersaldon stämmer överens med verkligheten. Saldoavvikelser är ett utbrett problem som kan påverka många olika delar av en verksamhet, såsom felaktiga underlag för inköp, den dagliga driften och företagets servicegrad. Fallföretaget Getinge Disinfection AB upplever främst att saldoavvikelser på företaget får effekt på den dagliga driften, något som denna studie ämnar undersöka. Syfte: Studien syftar till att identifiera konsekvenser och orsaker till saldoavvikelser på Getinge Disinfection AB samt ge förbättringsförslag som kan reducera saldoavvikelser på företaget. Metod: Denna studie har en kvalitativ forskningsstrategi. Vidare är studiens forskningsdesign en fallstudie då den endast undersöker ett fall ingående och detaljerat. Resultat: Studien fann att saldoavvikelser kan uppstå i alla steg i den studerade processen, med varierande primära orsaker i de olika stegen i processen. Bland de konsekvenser som funnits är de främsta icke-värdeskapande aktiviteter, opålitliga underlag för inköpsbeslut, OOS och ökade ledtider. Majoriteten av orsakerna grundar sig i den mänskliga faktorn, det vill säga att anställda inte följer rutiner eller gör misstag i processen. Dessa misstag kan ske i olika aktiviteter i processen och det finns olika primärorsaker beroende på var i processen misstaget sker. Vidare har författarna tagit fram förbättringsförslag för att effektivisera Getinge Disinfection ABs produktionsprocess. De mest lämpliga förbättringsförslagen är att skapa förståelse om saldoavvikelser bland de anställda, införa Cycle counting, digitalisera olika aktiviteter och utvärdera det nuvarande artikelsortimentet. Nyckelord: Saldosäkerhet, Saldoavvikelser, Producerande företag, Medicinteknik, Life Science, Assemble to Order, ATO, Cycle Counting, RFID, Streckkoder. / Abstract  Course: Degree project in Logistics, the Business Administration and Economics Programme, 30 credits, 4FE19E.    Authors: Jakob Bergman and Jim Andersson. Examiner: Peter Berling.  Tutor: Peter Berling. Co-judger: Hana Hulthén Title: Inventory record inaccuracies in manufacturing companies, a case study on Getinge Disinfection AB. Background: Effective inventory management is of considerable importance for most successful businesses. Without it, companies would be hard-pressed to meet the demands of consumers that place a high value on fast deliveries and product availability. As a result, businesses have turned to increased automation of their inventory management. This automation relies heavily on information such as inventory records being accurate and up to date. Inventory record inaccuracies result in purchases or decisions being made on incorrect assumptions of the companies’ actual inventory status, which has a negative effect on many aspects of the business. However, most studies on this subject focus on inventory record inaccuracies in a retailing context, whereas this study focuses on a large manufacturing company (Getinge Disinfection AB) using an Assemble to Order model. Purpose: The purpose of this study is to identify the different causes and consequences of inventory record inaccuracies (IRI) at Getinge Disinfection AB. Furthermore, the study aims to offer proposals on how to improve inventory record accuracy at Getinge Disinfection AB.    Methodology: This paper adopts a qualitative research strategy with a case-study approach.  Findings: The study concluded that inventory record inaccuracies can arise in all areas of the studied process, with different primary reasons for different stages of the process. Most of the causes of IRI can be attributed to the human factor, such as incorrect identification of the items, unregistered movements of goods, and transaction errors. The consequences of (IRI) were mainly the resulting non-value adding activities, purchasing decisions being made based on unreliable inventory data, stockouts and longer lead times. The study also gives suggestions on how Getinge could reduce these inventory record inaccuracies. Improvement measures such as Cycle counting, bar coding of the items and locations and increased staff training are discussed. Keywords: Inventory Record Accuracy, Inventory Record Inaccuracy, Manufacturing, Health Care, Life Science, Assemble to Order, ATO, Cycle Counting, RFID, Bar coding.