SIMULATING MATERIAL REQUIREMENTS PLANNING ON LOTUS 1-2-3 Developments in Business Simulation & Experiential Exercises, Volume 15, 1988 84 SIMULATING MATERIAL REQUIREMENTS PLANNING ON LOTUS 1-2-3 K. Kern Kwong, California State University, Los Angeles Precha Thavikulwat, California State University, Los Angeles ABSTRACT This paper discusses the suitability of simulating material- requirements-planning (MRP) problems on Lotus 1-2-3. It gives an example of such a simulation, suggests techniques to enhance user-friendliness, and proposes that students may be assigned to work with the template in number-entering mode or formula-entering mode. Because learning is profoundly affected by the extent to which students are motivated for performance or motivated for learning, the two modes may Induce different motivations, and consequently, lead to different effects on learning. INTRODUCTION Material Requirements Planning (MRP) is a computerized system for managing materials used in producing goods. Its importance in the study of manufacturing operations is well- recognized. Gaither (1986) has noted that “no course in (production and operations management] is complete today without a treatment of MRP” (p. 505). Although MRP is covered in several simulations (Able Associates, 1983; Greenlaw & Hottenstein, 1969; Fok, Kwong, & Hiranyawasit, 1987; Pray, Strang, A Burlingame, 1984) written in languages such as Fortran, Basic, and Pascal, the fact that MRP contains, as Dilworth (198b) notes, “no complex and sophisticated mathematical models” (p. 3C9) makes the subject suitable for spreadsheet simulation. In fact, simulation by spreadsheet is uniquely appropriate to the task because spreadsheet templates may be designed to allow students to enter formulas in place of or in addition to numbers, a feature difficult to implement in rudimentary computer languages. The difference between students entering numbers and students entering formulas into a simulation is not of trivial consequence. A student can enter numbers that work correctly while understanding little of the structure of the problem. The likelihood, however, that a formula entered without understanding will work correctly in any situation is exceedingly small, a lesson quickly learned by every beginning programmer. In essence, when students are required to enter numbers into a simulation, good performance is demanded of them, but when they are required to enter formulas, good learning is that which is demanded. Thus, motivation for performance or motivation for learning may be induced by the demands of a simulation. The qualitative difference in motivation so induced can, as Dweck (1986) has observed, have profound effects on learning. Recognizing the value of students entering formulas, Schroeder and Gentry (1987) suggested that students be required to develop their own templates for MRP. That approach, however, is feasible only if either the MRP system is exceedingly simple or several weeks of class are allocated to the task. In the case when a complex MRP system must be covered in a week, which is usual in most introductory courses in production and operations management, that approach is infeasible. This paper shows how a template for a complex MRP system can be created. It discusses several ways of making the template more “user-friendly,” and points out the possibility of judiciously encouraging motivation for learning by properly constructed students’ assignments. IMPLEMENTATION The essence of an MRP system is the proper organization of data so that material and capacity requirements can be computed readily from a production schedule. A complex MRP system consists of the following elements: 1. product-structure tree 2. routing file 3. Item master file 4. bill-of-materials file 5. work-center master file 6. master-production-schedule record 7. material-requirements-planning record 8. capacity-requirements-planning record Examples of these elements taken from our particular implementation is shown in Figures 1 through 8 below. Developments in Business Simulation & Experiential Exercises, Volume 15, 1988 85 TECHNIQUES FOR USER-FRIENDLINESS in implementing a simulation on a spreadsheet, the user- friendliness of the Implementation is important. An unfriendly implementation irritates, and becomes a hindrance to learning. A few of the less obvious techniques for making a spreadsheet template more user-friendly are discussed below, Use of Page-Up, Page-Down, Tab, and Shift-Tab Keys Lotus 1-2-3 displays a screen of 20 rows and a variable number of columns. By grouping items such that they consist or a complete unit of display within the confines of a screen, users may rely upon the paging and tab keys to page across displays. This makes it unnecessary to stroll the screen, which tends to cause disorientation. Developments in Business Simulation & Experiential Exercises, Volume 15, 1988 86 Prompt for Input Unprotecting cells for input in a 1-2-3 spreadsheet has the effect of accenting the cells by color or intensity, depending on the monitor in use. To call for input in these cells, the cell may contain a label, such as the following: B3: ‘ ____?____ In the first release of 1-2-3, formulas referencing labeled cells assigned the cells zero value; in the second release, however, such a reference results in error, indicated by ERR. To prevent such ERR’s from cluttering a template, reference to the labeled cell may be called through the second release’s @N function, as follows: B4: @N(B3) Informative Error-Trapping Messages Perhaps nothing else is so helpful in learning than the informative trapping of errors. The second release of 1-2-3 allows labels to be printed conditional upon calculations. This enables the template to include informative error traps, such as the following: B5: @IF(C4<0,” Not enough capacity.”,””) STUDENT ASSIGNMENTS Students can be assigned to work with the MRP template in two modes. In number-entering mode, the students would be told to change certain values, such as MPS Receipt on the Master-Production-Schedule Record, and observe the consequences on capacity, inventory, and cost. In formula- entering mode, the students would be told to enter formulas such as to yield the right values. In the first instance, the students would be taught to use a template; in the second, they would be taught to create one. The differential effects on motivating and learning of the two alternative modes have not yet been studied. SUMMARY The simplicity of the mathematics in MRP problems, and the complexity of relationships involved make such problems suitable for simulation in a spreadsheet. A unique advantage of using a spreadsheet for such simulations is the possibility of designing the spreadsheet such that students are required to enter formulas, instead of numbers. To implement an MRP system on a spreadsheet, the MAP data base must be carefully organized. Matters of user- friendliness must be addressed. Students assigned to work with the MRP template can be directed to work in number- entering mode or formula-entering mode. The differential effects of these two modes on motivation and learning are worth investigating. REFERENCES Able Associates (1983), TEAM, Bethel, CT: Author. Dilworth, James B. (1986), Production and Operations Management: Manufacturing and Nonmanufacturing (3rd ed.), New York: Random House. Dweck, Carol 5. (1986), “Motivational Processes Affecting Learning,” American Psychologist, 41, 1040-1048. Fok, Wing, Kern Kwong, and Chairat Hiranyawasit (1987), “Teaching Production and Inventory (PIM) Courses with PC-MAPICS” (Abstract), in E. C. Barnhart (Ed.), Conference on Computing in Undergraduate Education, Pittsburgh, PA. Gaither, Norman (1966), Production and Operations Management: A Problem-Solving and Decision- Making Approach (3rd ed.), Hinsdale, IL: The Dryden Press, 1986. Greenlaw, p. S. and M. P. Hottenstein (1969), PROSIM: A Production Management Simulation, New York: Harper & Row. Pray, T. F., 0. R. Strang, S. C. Gold, and D. E. Burlingame (1984), DECIDE-P/OM: An Interactive Computer Simulation for Production/Operations Management, New York: Random House. Schroeder, David L. and James W. Gentry (1987), “Teaching MRP Experientially Through the Use of Lotus 1-2-3,” Developments in Business Simulation and Experiential Exercises, 14, 179-182. Table of Contents Volume 15, 1988 The Role of Experiential Knowledge and Human Information Processing in Decision Making A Semantic Differential Instrument to Evaluate Experiential Teaching Methods A Comparison of Two Approaches to Management Skill-Building in an Organizational Behavior Course: A Replication Integrating Simulations: A Model for Business Policy Success Capstone Renaissance = Simulation + Interaction + DSS A Hybrid Method of Executing a Management Simulation: Combining the Best of Mainframes and Microcomputers Providing an Experiential Dimension to Cost/Managerial Accounting Courses Utilization of Computerized Tax Research Services in the Tax Research Curriculum Using and Expert System Based Decision Aid in Accounting Information Systems Event-Extended Entity-Relationship Diagrams for Understanding Simulation Model Structure and Function Multiple Objectives in the Development of the Gordon Macro Game A Comparative Study of Strategic Performance Factors in Actual and Simulated Business Environments An Empirical Investigation of Integrated Spatial-Proximity MCDM-Behavioral Problem Solving Technology Group Decision models Computer Simulation of Human Interaction The Role of Experiential Learning and Simulation in Teaching Management Skills Expert Systems - The New Business Simulation Tool Integrating Prolog into and Undergraduate Logistics Course Simulating Material Requirements Planning on Lotus 1-2-3 Innovation in Management Education: The Impact of the AACSB Experiential Learning in the International Environment Educational Testing with the Microcomputer A Simulation of Investment Analysis, Portfolio Management and Reporting Using Lotus 1-2-3 The Use of an Expert System to Develop Strategic Scenarios Two Exercises for Teaching about Motivation Sex Roles and the Good Manager A Form and Process for Nonconfidential Peer Evaluations Simulation and the Recalcitrant Student Employee Rights-Student Rights: A Classroom Exercise Computer Simulated Competition: An Alternative to Team Play Management Simulation The Relationship of Locus of Control and Vividness of Imagination Measures to Simulation Performance Formal Planning, Simulation Team Performance, and Satisfaction: A Replication Experimental Analysis of Magnitude and Source of Students' Inequitable Classroom Perceptions in Three Reward Conditions Strategy Design, Process and Implementation in a Stable/Complex Environment: An Exploratory Study Matching a Strategy Simulation to the Business Policy Literature: A Black Box Approach to Simulation Development An Evolutionary Classroom Experiential and Computer Simulation Model of a Corporate Strategic Planning System Collective Bargaining in the City of Elson: A Public Sector Experience Should Students Play Games in Labor Relations? Applying Cognitive Educational Objectives to Business Management Cases Grading as a Teaching and Feedback Mechanism: Involving Students in the Grading Process Teaching Controversies: A New Approach to Computer-Assisted Instruction and Simulation Packages Simulating Demand in and Independent-Across-Firm Management Game Advertising Response in the Gold and Pray Algorithm: A Critical Assessment A Model for Pricing Decisions in First Period Marketing Simulation Games Jog Your Right Brain: An Exercise for the Classroom and for Research Six Thinking Hats: An Exercise to Combat Confusion and Develop Thinking Skills Communicating in Context: A Simulation for Learning Business Communication A Simulated Consulting Service for the Compete Marketing Simulation Game Action Exams in the Consumer Behavior Class Using Focus Groups to Teach Problem Definition in Basic Marketing Research The Use of Journals in Management Simulations: A Literature Review and an ABSEL Response An Initial Step Towards Developing and Using an Expert System with a Business Simulation Self-Managed Learning: An Experiential Course Design Using the QWL Paradigm A Review of Current Developments in Experiential Learning Bring the Real World into the Classroom Assessing Student Performance on a Business Simulation Experience Minimizing Startup Anxiety: Case Studies of Simulation Experiences A Tale of Two Shepards Or Using Simulation in a Class Without Walls Enhancing Business Simulations Through the Utilization of Experiential Activities Involving Local Community Executives Simulation with Integrated Spreadsheets: The Design and Development of a Conversational Marketing Concepts Decision Game Introducing INMART: An International Marketing Simulation Using a Computer-Based Business Plan Assistant in Conjunction with a Marketing Simulation Game Overview of the ABSEL Guide to Experiential Learning and Simulation Learning