verification_validation

verification_validation - 1 SYSC 4005-5001 Winter 2010...

Info iconThis preview shows pages 1–9. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 1 SYSC 4005-5001, Winter 2010 Verification and validation of Simulation Models Winter 2010 Slides are based on the texts: -Discrete Event System Simulation, by Banks et al-Discrete Event Simulation: A first Course, by Leemis and Park 2 SYSC 4005-5001, Winter 2010 Model Validation ¡ The goal of the validation process is: ¢ To produce a model that represents true behavior closely enough for decision-making purposes ¢ To increase the model’s credibility to an acceptable level ¡ Validation is an integral part of model development 3 SYSC 4005-5001, Winter 2010 Model Verification ¡ Purpose: ensure the conceptual model is reflected accurately in the computerized(i.e software) representation. ¡ Many common-sense suggestions, for example: ¢ Have someone else check the model. ¢ Make a flow diagram that includes each logically possible action a system can take when an event occurs. ¢ Closely examine the model output for reasonableness under a variety of input parameter settings. (Often overlooked!) ¢ Print the input parameters at the end of the simulation, make sure they have not been changed inadvertently. 4 SYSC 4005-5001, Winter 2010 Summary: Verification-Validation ¡ Verification – building the model correctly (correctly implemented with good input and structure) ¡ Validation – building the correct model (an accurate representation of the real system) 5 SYSC 4005-5001, Winter 2010 Modeling-Building, Verification & Validation 6 SYSC 4005-5001, Winter 2010 Verification :Examination of Model Output for Reasonableness ¡ Example: A model of a complex network of queues consisting many service centers. ¢ Response time is the primary interest, however, it is important to collect and print out many statistics in addition to response time . ¡ Two statistics that give a quick indication of model reasonableness are current contents (e.g. instantaneous queuesize) and total counts (e.g. no. of arrivals in a period) , for example: ¢ If the current content grows in a more or less linear fashion as the simulation run time increases, it is likely that a queue is unstable ¢ If the total count for some subsystem is zero (or a constant), indicates no or the same number of items entered that subsystem, a highly suspect occurrence 7 SYSC 4005-5001, Winter 2010 Other methods for verification ¡ Compute certain long-run measures of performance, e.g. compute the long-run server utilization and compare to simulation results ¡ Use of a trace ¢ A detailed printout of the state of the simulation model over time. ¡ Experience and personal motivation is needed! 8 SYSC 4005-5001, Winter 2010 Calibration and Validation ¡ Validation involves the process of comparing (and improving ) the model and its behavior with respect to the real system....
View Full Document

This note was uploaded on 04/16/2010 for the course SCE sysc5001 taught by Professor Lambadaris during the Spring '10 term at Carleton CA.

Page1 / 27

verification_validation - 1 SYSC 4005-5001 Winter 2010...

This preview shows document pages 1 - 9. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online