Lab Module 01

Report
Learning Simio Lab Series 1
Lab Module 01
Evaluating Potential Modifications
to a Driver’s License Facility
Copyright © 2013 - Jeffrey S. Smith | All Rights Reserved
1
Objectives and Outline
• Objectives
– Learn the basics of:
• The Simio user-interface
• Modeling in Simio
• Using the Simio Pivot Grid
• Outline
1.
2.
3.
4.
5.
6.
Description of the system to be modeled
Introduction to the Simio user interface
Model the “current” configuration
Experiment and verify the current model
Model the “proposed” configuration
In-lab and take-home assignments
Video 1
Video 2
Video 3
Video 4
Video 5
Copyright © 2013 - Jeffrey S. Smith | All Rights Reserved
2
Drivers’ License Office
Check In
Applicants arrive
at a rate of
approximately
10/hour.
Performance Metrics:
• Server Utilizations
• Time In System
• Number In System
At check-in, a single
clerk checks
the applicant’s
driving history
(if any) and gives
the applicant the
initial paperwork.
Check-in takes
approximately 5
minutes.
Written
Exam
The written exam is
administered by one
of two exam clerks.
When an applicant
arrives, s/he waits for
an available clerk
and, once one is
available, takes the
exam with the clerk.
The exam requires
approximately 8.8
minutes.
Copyright © 2013 - Jeffrey S. Smith | All Rights Reserved
Check Out
At check-out, the
applicant completes
the process using
one of two check-out
computers and
receives his/her
temporary license.
Check-out takes
approximately 9
minutes.
3
Simio User Interface
•
•
•
•
•
•
•
•
Files Menu
Ribbons
Project Tabs
Libraries
Project
Current Model
Properties
Facility View
Copyright © 2013 - Jeffrey S. Smith | All Rights Reserved
4
Simio Standard Library
Source: Generate entities of a specified type and arrival pattern.
Sink: Destroy entities.
Server: Capacitated process, such as a machine.
Workstation: Capacitated process, includes setup, process, tear-down.
Combiner: Batches entities with a parent entity (e.g., pallet).
Separator: Splits batches or copies entities.
Resource: Seized/Released by objects.
Vehicle: Fixed route or on-demand pickups/drop-offs.
Worker: Moveable resource, for stationary and non-stationary tasks.
BasicNode: Simple intersection, fixed object input.
TransferNode: Change destination/get rides, fixed object output.
Connector: Zero travel time.
Path: Entities independently move at their own speeds.
TimePath: Entities complete travel in a specified time.
Conveyor: Accumulating/non-accumulating conveyor devices.
Copyright © 2013 - Jeffrey S. Smith | All Rights Reserved
5
Drivers’ License Office
Check In
Applicants arrive
at a rate of
approximately
10/hour.
Performance Metrics:
• Server Utilizations
• Time In System
• Number In System
At check-in, a single
clerk checks
the applicant’s
driving history
(if any) and gives
the applicant the
initial paperwork.
Check-in takes
approximately 5
minutes.
Written
Exam
The written exam is
administered by one
of two exam clerks.
When an applicant
arrives, s/he waits for
an available clerk
and, once one is
available, takes the
exam with the clerk.
The exam requires
approximately 8.8
minutes.
Copyright © 2013 - Jeffrey S. Smith | All Rights Reserved
Check Out
At check-out, the
applicant completes
the process using
one of two check-out
computers and
receives his/her
temporary license.
Check-out takes
approximately 9
minutes.
6
Drivers’ License Office
• So, we need to model:
– Applicant arrival process
Source
– Check-in process
Server
– Exam process
Server
– Check-out process
Server
– Applicant departure process
Sink
– Applicant transfer between processes
Path
Copyright © 2013 - Jeffrey S. Smith | All Rights Reserved
7
Build the Initial Model!
Copyright © 2013 - Jeffrey S. Smith | All Rights Reserved
8
Object Hierarchy - The Family of “Objects”
Object Instance
Object Runspace
(Realization)
Object
Definition
Copyright © 2013 - Jeffrey S. Smith | All Rights Reserved
9
Initial Object Properties
• Source1 (Source)
– Interarrival Time: Random.Exponential(6) ; units: Minutes
• CheckIn (Server)
– Initial Capacity: 1 (default)
– Processing Time: Random.Exponential(5) ; units: Minutes
• Exam (Server)
– Initial Capacity: 2
– Processing Time: Random.Exponential(8.8) ; units: Minutes
• CheckOut (Server)
– Initial Capacity: 2
– Processing Time: Random.Exponential(9) ; units: Minutes
• Sink1 (Sink)
– All defaults
Copyright © 2013 - Jeffrey S. Smith | All Rights Reserved
10
Editing Properties
•
•
•
•
Displayed in Properties Window
Defined by object builder
Integers, Booleans, rules, expressions, …
Expression editor (down arrow at right):
Copyright © 2013 - Jeffrey S. Smith | All Rights Reserved
11
Drivers’ License Office
Check In
Applicants arrive
at a rate of
approximately
10/hour.
Performance Metrics:
• Server Utilizations
• Time In System
• Number In System
At check-in, a single
clerk checks
the applicant’s
driving history
(if any) and gives
the applicant the
initial paperwork.
Check-in takes
approximately 5
minutes.
Written
Exam
The written exam is
administered by one
of two exam clerks.
When an applicant
arrives, s/he waits for
an available clerk
and, once one is
available, takes the
exam with the clerk.
The exam requires
approximately 8.8
minutes.
Copyright © 2013 - Jeffrey S. Smith | All Rights Reserved
Check Out
At check-out, the
applicant completes
the process using
one of two check-out
computers and
receives his/her
temporary license.
Check-out takes
approximately 9
minutes.
12
Run Length and Pivot Grid
Copyright © 2013 - Jeffrey S. Smith | All Rights Reserved
13
Expected “Results” – Static Model
Arrival Rate (per hr)
10
IAT (mins)
6
Check-in
Exam Check-out
Overall
Split
100.0%
100.0%
100.0%
Capacity
1
2
2
Process Time (mins)
5
8.8
9
Process Rate (per hr per unit)
12.0
6.8
6.7
Utilization
83.3%
73.3%
75.0%
Num at Station (L)
5
3.2
3.4
11.6
Time at Station (W - mins)
30
19.2
20.4
69.6
Copyright © 2013 - Jeffrey S. Smith | All Rights Reserved
22.8
14
Drivers’ License Office
Check In
Applicants arrive
at a rate of
approximately
10/hour.
Performance Metrics:
• Server Utilizations
• Time In System
• Number In System
At check-in, a single
clerk checks
the applicant’s
driving history
(if any) and gives
the applicant the
initial paperwork.
Check-in takes
approximately 5
minutes.
Written
Exam
The written exam is
administered by one
of two exam clerks.
When an applicant
arrives, s/he waits for
an available clerk
and, once one is
available, takes the
exam with the clerk.
The exam requires
approximately 8.8
minutes.
Copyright © 2013 - Jeffrey S. Smith | All Rights Reserved
Check Out
At check-out, the
applicant completes
the process using
one of two check-out
computers and
receives his/her
temporary license.
Check-out takes
approximately 9
minutes.
15
Proposed System Modification
Check In
Written
Exam
Check Out
Add an optional “computerized exam
kiosk” to replace one of the two clerks.
Applicants would have a choice between
the exam administered by a human clerk
and the computerized exam.
The computer kiosk will support two
exam-takers at a time.
Initially, assume that ½ of the applicants
choose the kiosk and that the exam time
is the same as with the human clerk.
Copyright © 2013 - Jeffrey S. Smith | All Rights Reserved
16
Build the Proposed Configuration Model!
Copyright © 2013 - Jeffrey S. Smith | All Rights Reserved
17
In-Lab Assignment
Server Utilizations
Ck-In
M-Exam
C-Exam
Ck-Out
NIS
TIS
Current
Proposed A
Proposed B
Proposed C
• Proposed A - Exponential exam times for both
• Proposed B – Reduced variance on the exam times:
• Human – Random.Triangular(6, 8.8, 11.6)
• Kiosk – Random.Uniform(6, 11.6)
• Proposed C – Same as B, but send 70% to the kiosk (hint: use Selection
Weights on the alternative paths leading from check-in)
• For each metric, report the average and confidence interval half-width (h)
based on 25 replications, each of length 1000 hours with a 500 hour warm-up.
Copyright © 2013 - Jeffrey S. Smith | All Rights Reserved
18
Homework Assignment
• Starting with the “Proposed C”
configuration from the in-lab
assignment, implement the
following exam failure logic:
– When an applicant fails the
exam, s/he returns to re-take
the exam. The applicant
should return to the same
exam station (either human
or computer)
• Using your modified model,
determine the maximum
percentage of exam failures
that the system can support
before becoming unstable
(where the exam servers
cannot keep up with the
arriving applicants).
• Consider a walk-up bank that that has an ATM, a single teller,
and a manager.
• ATM customers visit the ATM and teller customers visit the
teller.
• 10% of customers (regardless of original type) visit the
manager after visiting the ATM or teller.
• Arrival and service time properties are:
– ATM customers arrive at the rate of 10/hour and spend
approximately 4 minutes at the ATM
– Teller customers arrive at the rate of 5/hour and spend
approximately 7 minute at the teller
– Customers that visit the manager spend approximately 20
minutes with the manager
• Run 25 replications for 2000 hours each (no warmup) and
determine the server utilizations and the times that the
customers spend in the system (ATM customers, teller
customers, customers that see the manager)
Copyright © 2013 - Jeffrey S. Smith | All Rights Reserved
19

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