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Extension of Rescheduling based on Minimal Graph Cut. Mari án Lekavý and Pavol N ávrat. Slovak University of Technology Faculty of Informatics and Information Technologies. Presentation outline. Rescheduling RAPORT overview The rescheduling algorithm Future and Conclusions. Rescheduling.
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Extension of Reschedulingbased onMinimal Graph Cut Marián Lekavý and Pavol Návrat Slovak University of TechnologyFaculty of Informatics and Information Technologies
Presentation outline • Rescheduling • RAPORT overview • The rescheduling algorithm • Future and Conclusions
Rescheduling • Schedule is not 100% respected • Move/shorten activities • Minimize the cost of rescheduling
Rescheduling • Approaches • Enforce schedule • Include all possibilities • New schedule • Modify the old schedule
Rescheduling • Modify the old schedule • RSR (Right Shift Rescheduling) • PR (Partial Rescheduling) • Unmovable deadline • Time reserves (e.g. Match-Up Rescheduling) • Shortening of activities
RAPORT • Workflow system • Support formilitary exercise preparation • Tasks of the RAPORT system • Provide necessary information • Support collaboration • Adapt the schedule • Collect users’ experience
RAPORT • Activities and documents in the RAPORT system
The problem Increase the end time of some activity (activities) while not moving the final deadline. • Move activities • Shorten activities
The problem • Input: activities • Time (start, end, minimal) • Activity dependencies (documents) • Activities which violate the schedule • Output: minimal cost rescheduling • Moved and shortened activities
Rescheduling as graph cut • Rescheduling by 1 time unit • two sets of events: moved and unmoved • Graph cut • two sets of vertices divided by the graph Rescheduling can be converted to graph cut
Algorithm example 1. Conversion to graph
Algorithm example 2. Adding activity edges
Algorithm example 3. Adding the final node
Algorithm example 4. Edge costs
Algorithm example 5. Find the minimal cut
Algorithm example 6. Moving of activities
Edge costs • Abort the failed activity • ∞ • Shorten an activity • 1/∞ • Shorten a dependence • 0/∞ • Move an activity • 0.001/∞ • Move the deadline • ∞
Further work • Testing in NAO • Automatic cost adjusting • k-step optimal rescheduling • Combination with CPM/PERT • Resources (resource links?)
Conclusions • Every rescheduling corresponds to agraph cut • New rescheduling algorithm • Minimal cost of change • Works with moving and shortening ofactivities