tailieunhanh - Lecture Operations management (6th Edition): Supp A - R. Dan Reid, Nada R. Sanders

In this chapter you will: Describe the conditions under which MRP is most appropriate; describe the inputs, outputs, and nature of MRP processing; explain how requirements in a master production schedule are translated into material requirements for lower-level items;. | Supplement A – Spreadsheet Modeling: An Introduction Operations Management 6th Edition R. Dan Reid & Nada R. Sanders 1 Copyright © 2016 John Wiley & Sons, Inc. Learning Objectives Explain what models are and why they are used. Describe the spreadsheet modeling process. Describe multiple-criteria decision making with spreadsheet models. Explain different useful spreadsheet tips. Demonstrate important Excel formulas. What are Models? Models are used for decision making Mental Models (. traffic light) Visual Models (. graphics or diagrams) Physical Models (. architect’s scale bldg.) Mathematical Models (. use equations) Spreadsheet Models (. mathematical) Model Characteristics Inputs: quantities or factors that affect a decision Controllable Inputs (decision variables) Uncontrollable Inputs (parameters) Outputs: Primary & secondary, calculated from inputs and is of interest to the decision maker Model Definition A model is a purposeful . | Supplement A – Spreadsheet Modeling: An Introduction Operations Management 6th Edition R. Dan Reid & Nada R. Sanders 1 Copyright © 2016 John Wiley & Sons, Inc. Learning Objectives Explain what models are and why they are used. Describe the spreadsheet modeling process. Describe multiple-criteria decision making with spreadsheet models. Explain different useful spreadsheet tips. Demonstrate important Excel formulas. What are Models? Models are used for decision making Mental Models (. traffic light) Visual Models (. graphics or diagrams) Physical Models (. architect’s scale bldg.) Mathematical Models (. use equations) Spreadsheet Models (. mathematical) Model Characteristics Inputs: quantities or factors that affect a decision Controllable Inputs (decision variables) Uncontrollable Inputs (parameters) Outputs: Primary & secondary, calculated from inputs and is of interest to the decision maker Model Definition A model is a purposeful representation of the key factors in a situation and the relationships among them. So, it: is an abstraction of a real situation provides enough detail so results meet current needs omits unnecessary details Spreadsheet Modeling Process Turn off the computer. Draw a picture/diagram, identify controllable & uncontrollable inputs, outputs. Sketch out overall plan for spreadsheet model. Determine where inputs, intermediate calculations, and outputs will go. Develop the base case spreadsheet model. Test the model using trial values. Use the model to perform the needed analysis. Document the model so others can understand it. Spreadsheet Modeling Process- cont’d The needed analysis from step #5 includes: Sensitivity analysis – helps to identify the inputs that cause the most change in the output Scenario analysis – helps a decision manager gain additional insight into a situation Evaluating Spreadsheet Models Correct Correct numerical answer for base case (., “given” .