17.2: Points Made in the Case Study

Last updated
Save as PDF

Page ID: 31030

\( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)\(\newcommand{\AA}{\unicode[.8,0]{x212B}}\)

Simulation can be used to assess the operational behavior of a system designed by other means. In this case, the AGV system is designed using standard, analytic methods. Simulation is used to assess the behavior of the system as designed relative to operational performance criteria as well as to determine the number of vehicles the system needs.

The structure of a system can be described using data inputs to a model. This allows changes in system structure to be assessed without changing the model. In this case, the control segments and control points are defined by input data. This data input most often takes the form of a graphical drawing.

The models originally developed for operations can be directly applied to material handling situations as well. This illustrates how models developed for one domain may be directly applied to another domain where system components behavior and interact in an analogous way. In an AGV system, the control points constrain the movement of the vehicles to assure that there are no collisions at interactions. Thus, control points can be modeled as a single machine station where the processing time is the time to traverse the control point.

Increasing the number of resources that can perform an activity, such as the number of machines at a workstation, normally lessens entity waiting time for that activity. Thus, it might be assumed that increasing the number of vehicles in an AGV system would increase the responsiveness to movement requests. This might not be the case since the contention between the AGV's for control segments, and control points will increase.