SEA TAC example

• 2 types of customers, coach arrival rate exp m=1min & 1st class arrival rate uniform 4-5min. 1 Q for each class of customer, 1 server for 1st class uniform 5-8 mins, 4 servers for coach, 1@ normal m=15 sd=5, 3@ uniform 5-10 min. How long each type of customer in line

Chapt 7 (portions)

• Read/ Write Nodes (pgs 222-228)

• Assembly Modeling (pgs 239-262)

• Accumulate Node

• Batch/ Unbatch Node

• Control Statements

Interface & Assembly

• Build on Basic concepts from chapters 5 & 6• Able to integrate/ interface software with other programs• Provided by reading inputs from files, spreadsheets, databases• Then outputted to files, spreadsheets…..

• Able to model the assembly of entities into a single entity ie CPM, collect up to a certain # then release entities• Also retrieve entities that were combined, ie separate parts after they were batched together for a specific process

Read Node

• Used to read one or more values from an external file• Table 2.9 Users Guide

Node = readin

Read from spreadsheet

three columns of data

3 branches

Write Node

• Used to write values to an external file ie .xls

Called sentoxls

put in file called airportque.xls

send TNOW & ATRIB(2)

real values 3 + decimal pt + 1 following

Write Example

• Single server to obtain table with 4 columns, entity #, arrival time, wait time, system time

Assembly Modeling

• Wait until four units of a order arrive before boxing and shipping • Start an operation that needs one bolt, one washer, one nut, spud wrench• Start activity “pour foundation” once activities of unslab elect, underslab, plumb, gravel & compact are completed• Accumulate• Batch• Unbatch

Accumulate Node

• Collect entities until a certain number are reached• When achieved the node is released

FR # til 1st release

SR # til subsequent release

Save atrib of entity of:

# of branches

• Pert example

• Pert example

Batch Node

• Collect entities until a certain number are is reached• Then release a single entity that represents the batch• Typically used for modeling pallets and loads of cars/ trucks that accumulate before

moving

Batch from when

Collecting values on ATRB..then released

Sorted on /default 1

UnBatch Node

• Put entities of a batch back into the network or split an entity into multiple units

• Individual entities of the batch are restored

• Batch Unbatch example

• Batch Unbatch example

Chapt 7 examples

• Read example• 7-1 read the following into a model, valuse of ATRIB[0], ATRIB[1]

and LTRIB[1] from file ATTRIBUTES.DAT for 1000 entities

Chapt 7 examples

• Write example• 7-2 (b) write out the values of current simulated time, the first real attribute,

and the first integer attribute of the current entity to the file TRACE.DAT

Chapt 7 examples

• 7-9 Use ACCUMULATE to:a) all preceding activities must be completed before a successor can be started, b) any one activity must be completed before a follow one activity can be completed, c) 3 out of 5 activities must be completed before an activity can be completed

• a)

3 predecessors

Chapt 7 examples

• 7-9 Use ACCUMULATE to: b) any one activity must be completed before a follow one activity can be completed, c) 3 out of 5 activities must be completed before an activity can be completed

• b)

1 predecessors

Or use

Chapt 7 examples

• 7-9 Use ACCUMULATE to:c) 3 out of 5 activities must be completed before an activity can be completed

• c)

1 predecessors

PERT Example

• Collect entities until a certain number are is reached• When achieved the node is released• Concrete slab after excavation

Vapor Barrier

Form

WWF

CompactGravel

U/S plumb

U/S elect activity Des Min Mode max

1 Gravel 1 2 32 U/S plumb 2 3 5

3 U/S elect 2 3 54 Compact 2 3 45 Form 3 4 56 WWF 1 2 37 Vapor b 1 2 3

PERT Example

• Concrete slab after excavation

Control Statements

• Class assignment• simulate model shown in figure 7-1 of book• show out put on xls chart• due 11/26

Where are we going

• Skip Chapt 8, will do Chapt 9 11/19• Chapt 10 11/26• No class 12/3• Projects due 12/10