Ana Luísa Ramos 1 , Mélodie Palhares 2 , Carlos Ferreira 2

1. A SUCESSFUL PROBLEM-BASED LEARNING ENVIRONMENT: THE CASE OF A SIMULATION-BASED ASSEMBLY LINE DESIGN ANALYSIS Ana Luísa Ramos1, Mélodie Palhares2, Carlos Ferreira2 1University of Aveiro – Department of Economics, Management and Industrial Engineering / GOVCOPP Research Unit (PORTUGAL) 2 University of Aveiro - Department of Economics, Management and Industrial Engineering (PORTUGAL)

2. Outline 1 Presentation of the theme 2 Problem-based learning environment and simulation 3 The case study: A simulation-based assembly line design analysis Objective Alternative Scenarios Analyses and Decision 4 Conclusions

3. Presentation of the theme The students of the master programme in Management and Industrial Engineering of University of Aveiro take a one-year business internship in a Portuguese company and the Advanced Simulation course helps them to develop a simulation study to solve real world problems that they encounter during their internship experience. This simulation of the real-world experience is a way of active learning which provides a considerably memory recollection. Several works in the literature help support the notion that games and simulation studies are an effective active way of teaching production-related concepts. This problem-based learning method aims to prepare the students to solve engineering problems in real business environments using proper industrial engineering tools and methods and establishing effective communications channels between the university and the companies involved in the programme.

4. Problem –based learning environment and simulation The new virtual generation (V-gen) is more visual, interactive and focused on problem-solving than the former generations so, the graduate programmes in engineering need to adopt new teaching/learning paradigms based on experiential, and problem-based approaches. Simulation is the second most widely used technique in operations management (after Modelling) and its appropriateness for practical real-world applications is remarkable as there is a growing need to address the complexities of the whole and to deal with different layers of decision-making within a system. Due to the dynamic, computer-based, visual, and problem-solving nature of simulation, the simulation courses have been used, in the last years, to implement new learning approaches focused on the student and focused on active experiential practices based on real problem-solving. This work describes a particular case of this successful learning paradigm and successful interaction between the academia and the industry accomplished through the simulation course (Advanced Simulation) of the Management and Industrial Engineering (MIE) graduate programme at University of Aveiro, in Portugal.

5. The case study:A simulation-based assembly line design analysis Mercatus is specialized in the production of refrigerated food service equipment, mainly refrigerated counters, cabinets and cold rooms for the HORECA sector (the sector of the food service industry HOtel/REstaurant/CAfé). The assembly line studied is dedicated to the assembly of the refrigerator group for the cold rooms. This line is constituted by three workstations only dedicated to the assembly of the final product and one workstation (pre assembly) dedicated to the assembly of sub products (this workstation doesn’t work full time to this assembly line). The pre assembly workstation is located in another section of the factory where the pre assembled components are produced and stored (work-in-process) until they are required in the assembly line. Layout of the assembly line

6. The case study: Objective The objective of this work was, using a discrete-event simulation-based (DES) approach, to analyze a given assembly line in order to increase its throughput and overall productivity. Data of the current assembly line operation (95% confidence intervals)

7. The case study: Alternative Scenarios The study involved the comparison of two design alternatives for the assembly line and the selection of the best scenario for a given set of performance measures. System layout for scenario A System layout for scenario B

8. The case study: Alternative Scenarios Output data for scenario A When considering the different alternatives scenarios to compare, the option of consider the pre assembly workstation fully dedicated to this assembly line was excluded because it uses expensive equipment that is also is required to pre assemble materials for other assembly lines. Output data for scenario B

9. The Case Study: Analysis and Decision Comparative table for the different results • Increase of productivity that rounds 30%; • Queue statistics reveal a better performance for all the workstations; • Reduction in the area (of about 65%) occupied by work-in-process in the pre assembly area; • Workstation 2 continues to be the bottleneck but the worker responsible for the workstation 1 will continue to help the workstation 2 when there is some available time and/or the work-in- process reaches up to 2 units. Scenario B

10. Conclusions This work is the outcome of a successful collaboration between the academia and the business world through the business internship program sponsored by the University of Aveiro (and the Advanced Simulation course of the master programme in Management and Industrial Engineering). The student who developed the study was critical in the process as she combined the knowledge of the simulation tool being used with the awareness gained on the assembly line operation details. The company's goals were fully attained and, to best prove it, the suggested modifications are being implemented, as a result of the outcome of the simulation study. This work can be used to show the benefits that companies can get from these collaborative studies. The study can also be used to evidence the successful university/industry interaction and the advantages that can be gained through the use of simulation to design and analyze manufacturing systems.