Lafayette Crisis Center Scheduling System Project 2 1

Introduction  Patryk Ozga, Computer Science,  Sahaj Saini, Computer Science,  Richard Reasons, Computer Science, LCC scheduling system 2

Agenda  Partner Profile  Project Specifications  Approach – Algorithmic Choices  Development and Testing Strategy  Future Plans 3

Partner Profile  Lafayette Crisis Center (LCC) – local crisis hotline  70+ volunteers/month  5x7 shifts per week  2 organizers Goal: replace manual scheduling LCC scheduling system 4

Scheduling System  The problem is to create monthly schedules for volunteers at the Lafayette Crisis Centre  The schedule must respect the scheduling constraints followed by the Lafayette Crisis Centre  The schedule must be fair to the volunteers based on their preferences 5

Project History  Project began in August 2009  Contact person at LCC is Jane McCann, Executive Director  Designed to use Visual Basic and Python to generate a schedule based on volunteer preferences 6

Goals of the project  We hope to use the scheduling software to: Create accurate and reliable results that will satisfy volunteers Eliminate continual reanalysis of scheduling data Keep scheduling familiar & simplified LCC scheduling system 7

Success Criteria  Overall objective More efficient scheduling system that will save time and effort The schedule will accurately fit volunteers’ preferences Provide administrator with customizable final schedule LCC scheduling system 8

Project Specifications  Provide input method for preferences Shift availability, requested hours, days off  Restrict availability criteria Shift frequency, workers per shift  Provide externally modifiable calendar 9 LCC scheduling system

Project Stage Analysis Project Background  Conceptual Design  Detail Design  Delivery  Service & Maintenance Current Status  Conceptual Design  Detail Design  Delivery  Service & Maintenance 10

Old Operational Overview LCC scheduling system 11

Previous Approach  Non-integrated programming environment Python, Visual Basic Scripting requirements  Non-Maintainable It would be hard to trace problems in case this code breaks Recovery would take a lot of time – might have to be done by different people who do not understand the code  Non-extendable coding approach Algorithm itself non-extendable Future change in project specifications or other variables might break the code Current changes in project specifications are almost impossible to incorporate Rules out the possibility of extension to a Web-based version in the future 12 LCC scheduling system

New Approach  Integrated programming environment C#  Object-Oriented  Robust  Portable No Scripting requirements  Extendable coding approach Implement new features Duplicate it to different organizations Extend to a web-based version 13 LCC scheduling system

New Operational Overview LCC scheduling system 14 GUI / Algorithm iCal

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Constraints  The 5-day constraint Volunteers should not be scheduled for more than 1 shift within any 5-day period.  The days-off constraint Volunteers should not be scheduled for any shifts on their days off 18 LCC scheduling system

Constraints  The 1-shift-a-month constraint Each volunteer should be scheduled for at least 1-shift a month, unless overridden by all days-off  The must-work constraint Volunteers must be assigned to their must-work shifts if any 19 LCC scheduling system

Constraints  The day-shift constraint No more than 2 volunteers should be assigned to day shifts.  The night-shift constraint No more than 1 volunteer should be assigned to a night shift.  The training-period constraint Volunteer under a training period i.e. who have worked fewer than 39 shifts, should be scheduled for at least 1-shift a week. 20 LCC scheduling system

Old Algorithm  Hill Climbing Algorithm Nondeterministic Optimizes arbitrary scale Not suited for extensive constraints LCC scheduling system 21

New Algorithm  Restricted Priority Algorithm Find Most Restrictive Shift Find Most Restrictive Volunteer for Shift Assign Volunteer to Shift Update Program State Iterate LCC scheduling system 22

Methodology  Restrictiveness  Stopping Criterion  Inflation LCC scheduling system 23

Shift Restrictiveness  Determined by the number of volunteers and their preferences for the shift  (# of volunteers) * (sum of preferences for shift) LCC scheduling system 24

Volunteer Restrictiveness  Determined by: Scheduled for at least one shift Number of Shifts per month Number of shifts per week Training period Weighted inflated preferences LCC scheduling system 25

Stopping Criterion  All shifts are filled  No more volunteers to assign  Empty shifts conflict with volunteers’ preferences LCC scheduling system 26

Inflation  Volunteers usually do not choose highest/lowest values in the preference range  Need to normalize the preferences to schedule accurately  Optimize the volunteer preference chart to give everyone a fair shot on being accurately scheduled LCC scheduling system 27

Testing Strategy - Algorithm  Use multiple real data sets  Estimate weights of restrictiveness parameters  Generate calendars and analyze them for discrepancies  Compare results between trials to perfect parameters 28

Testing Strategy - Calendars  Generate calendars based off real volunteer data  Test calendars against project specifications  Meet with project partner to spot problems  Iterate 29

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Next Semester  Implement re-designed algorithm  Test and optimize the algorithm  Test calendars against project specifications  Deliver a prototype 32

Questions? LCC scheduling system 33