Extendsim Examples | Mind Map

Measures

wait time

queue modeling blocks

utilization

resource blocks

Count Items block

number of items that routethrough a certain path

various statistics blocks

don't need to be connected;just present

collect data from blocks thathave a delay or processingtime (Operation, Stack, etc.)

Queue Stats block

from DE lib

ave queue length, max Qlength, ave wait, max wait time

Resource Stats block

from DE lib

collects from resourcetypeblocks like Repository, LaborPool

resource utilization

Costs Stats block

from DE lib

info on costing blocks like Operations

cost per item, cost per unit oftime, total cost

Cost by Item block

from DE lib

cost info for every block that passesthrough the block (must beconnected)

cost of each item

connectors

average cost

current cost

total cost

Mean &amp; Variance block

calcs average and std dev forthe simulation

connect to plotter to see ave over time

Activity Stats

Plotters

Plotter, DE block

four inputs on discrete events

value

time value (when it happened)

use Show Instantaneous Lengthoption if connected to L onStack

Histogram

connect L from Stack

Length column is length of queue

adjust bins; often 6

Special Blocks

Executive

must farthest to the left

required for all simulations

controls timing and passing of events

Input Random Number block

from Generic lib

uses probability distributions

connect to D input onOperations block (delay)

Models share certain concepts

Selection of time units

Length of a run

Number of runs

Model verification

Model validation

Batching

Operation block

Batch block

batch up to three items into asingle output

Unbatch block

separate up to three item

used to separate resource from the item soitem can go forward and resource back topool

when batch/unbatch, checkPreserve Uniqueness

Items

Import block

generates arrivals

specify arrival pattern

specify amount per arrival

alternative would be Generator block

Input Data block

changing arrival rate basedon exponential distribution

Program block

schedule specific arrivals atspecific times

Attributes

set via

Input block

easiest

Operation block

Repository block

Labor Pool block

Program block

Set Attribute blocks

carry through entire process

Prioritizing items

Stack block

choose type of stack

other methods?

Repository block

holding area (think inbox)

can start with some items

assign attribute and priority asthey leave

can't measure wait time; useStack block instead

items leave FIFO

Export block

Operations block

simulates an activity

delays item passing through

delay time constant unlessInput Random Number isattached

Transaction block

alternative to Operations formodeling parallel servers

also used to model multiplesimultaneous activities

Block types

model activities

model resources

model routing

collect data

calculate stats

display output

Model Building Steps

Determine goals

Understand process to be modeled

Draw a block diagram of process

Specifiy parameter values

Define logic of model and connections

Validate the model

Add data collection andgraphical analysis

Analyze output and draw conclusions

Activity blocks

Transaction block

allow for parallel processing

Activity Multiple block

allow for parallel processing

used to model transportationactivities like mailing, emailing,faxing docs