This document provides guidance on data collection for simulation modeling. It discusses collecting existing data from various sources, performing preliminary data collection to understand the system, and detailed data collection to determine key aspects of how the system operates. Recommendations are provided on focusing data collection, collecting enough data for statistical analysis, continuous data collection over various time periods, and using multiple collectors to observe without interfering with the system. An example of data collection for a single queue system is also included.

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2. Existing Observation
 Computer Files
◦ Database
◦ Spreadsheets
◦ Raw Data
 Video Records
 Hard Copy Files
& Documents
 Interviews
 Video
 Observation of
running system
 Interviews
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3. Preliminary Detailed
 To help design
model
 Interviews
 Observation
 Minimum
necessary
 To obtain input
parameters
 Adequate
amount for
statistical tests
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4. Preliminary Detailed
 Data to Determine
◦ Layout of system
◦ Entities of
importance
◦ Flow of entities
◦ Problems
 Rough estimates of
times
 Data for
◦ Arrivals
◦ Services
◦ Queues
◦ Anomalies
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5.  Focus on data related to problems &
objectives
 Enough data for statistical significance
 Continuous data
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6. Depends on Simulation Objectives &
Level of Activity
 Days of week
◦ Busiest, Typical, Slowest
◦ All, Certain ones
 Time of day
◦ Busiest, Typical, Slowest
◦ Start-up, Wind-down
 Length of time
◦ Adequate numbers
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7.  Minimum of 2 collectors for each
major entity
◦ One watches & times; One records
 Factors
◦ Level of Activity
◦ Proximity of areas to be observed
◦ Visibility
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8. Collectors can have NO Effect on the
system!
 Should be located “outside” the
system
 Cannot utilize any resource
 Never interfere
 Best if not seen
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9.  Collect information necessary to
reproduce system activity
◦ NOTE: That is not everything!!
 Example: Single Queue & Server System
◦ Arrival Time, Begin Service, End Service
◦ Allows calculation of all remaining values
of interest. How?
 Time Units
◦ Smallest necessary (seconds, minutes…)
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10. Customer
Number
Arriva l Time
Hr:Min:Sec
Begin Service End Service
1 0:0:0 0:0:0 0:5:26
2 0:3:30 0:5:26 0:10:45
3 0:12:0 0:12:0 0:15:50
4 0:13:24 0:15:50 0:19:55
Comments??
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11.  A description of process that includes
◦ Method(s) for collection
◦ Timeline for data collection process &
completion
◦ List of data items to be collected
◦ Number of collectors
◦ Dates & times of actual data collected (if not
observed in real-time)
◦ Justification for each of the above
◦ Diagrams as necessary
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12.  A description of completed collection
process that includes
◦ Restatement of “Plan” & any changes to
original plan
◦ Results of Statistical Analysis of data
 Graphs, Averages, Max, Min
◦ Summary of results
◦ Relation of results to clients objectives
◦ Recommendations
◦ Diagrams as necessary
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13.  Select System
 Design & Write Data Collection Plan
 Observe & Collect
 Complete Data Analysis
 Write Data Collection Report
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