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M/M/c Queuing Simulation with VBA (1). Business Process Modeling, Simulation and Design. Overview. Problem (VBA Assignment 1) Logics – Flowchart Main Sub Arrival Sub ServerOpen Sub Report, and others Coding Flowchart. Problem.
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M/M/c Queuing Simulation with VBA (1) Business Process Modeling, Simulation and Design
Overview • Problem (VBA Assignment 1) • Logics – Flowchart • Main Sub • Arrival Sub • ServerOpen Sub • Report, and others • Coding Flowchart
Problem • Spreadsheet simulation usually means creating a spreadsheet model with random numbers (e.g. exponential) in certain cell and then replicating the model with a data table and add-in such as VBA. • Multi-server queuing system is very difficult to model with spreadsheet formulas because of the timing and bookkeeping involved (like which server has finished the service). • A more natural approach is to take care of all the model’s logic in VBA and then simply report the results on a worksheet.
User Inputs Outline of the Simulation • Arrival Rate (λ) • Multiple Servers (c) with identical service rate (μ) • Single line queue • Limited time length (no more customers at some point of time) • Limited queue length (?)
Output • See example Sample output.xls • To get these values in the end, what variables should be kept for each event?
Logic Flowchart • Main Sub • Structure the entire logic • Subroutines are used to hide unnecessary details • Think logics first before translating into coding http://www.nku.edu/~sakaguch/ifs494/Main Sub Flowchart.vsd