Develop a conceptual model for this problem outlining the objectives, experimental factors and responses, model scope and level of detail, and assumptions and simplifications.
ATM Illustration: The Problem Situation
• There are spaces for up to six ATMs in new branch of bank.
• Three types of ATM can be purchased
• The bank has a policy that customers should not wait for more than 5 minutes.
ATM Illustration: Modeling Objectives
• Each ATM working during each period of the day to ensure that 99% of customers should not wait for more than 5 minutes.
• There are 3 types of ATM for customers to choose.
ATM Illustration: General Project Objectives
Time-scale Everyday working (all time)
Flexibility Limited (extensive changes unlikely)
Run-speed Many experiments to be run
Visual display Simple 2D
Ease-of-use Use by each user only
ATM Illustration: Model Inputs
• Staff rosters (total number of staff in each hour of the day), varied over a range of 1 to 6.
ATM Illustration: Model Outputs
Outputs (to determine achievement of objectives)
• Percentage of customers queuing for less than or equal to 5 minutes
Outputs (to determine reasons for failure to meet objectives)
• Frequency diagram of waiting time for each customer in the queues, mean, standard deviation, minimum and maximum
• Time-series of mean queue size by hour
ATM Illustration: Model Scope
Component Include/Exclude Justification
Customers Include
ATM
- Service
- Money
- Queue