Dag Kjenstad

A Blackboard Architecture for Integrating Process Planning and Production Scheduling

As companies attempt to increase customization levels in their product offerings, move toward smaller lot production, and experi ment with more flexible customer/supplier arrangements such as those made possible by electronic data interchange (EDI), they increas ingly require the ability to (1) respond quickly, accurately, and competitively to customer requests for bids on new or modified products and (2) efficiently work out supplier/subcontractor arrangements for these products This in turn requires the ability to (1) rapidly convert standard-based product specifications into process plans and (2) quickly integrate process plans for new orders into the existing production schedule to best accommodate the current state of the manufacturing enterprise

The Practice and Theory of Automated Timetabling (2012)

This special volume is focused upon a selection of the papers that were presented at the 9th International Conference on the Practice and Theory of Automated Timetabling (PATAT) in Son, Norway, between 28th and 31st August, 2012. The PATAT conferences are held biennially. This is the third occasion that we have employed the Annals of Operations Research as the forum for a revised and selected collection of papers. The first and second PATAT special volumes of this journal (Volumes 194 and 218) represented the 7th and 8th conferences, held in Montreal in 2008 and in Belfast in 2010, respectively. The PATAT series has been running since 1995. It has been held in Scotland, Canada (twice), Germany, Belgium, USA, Czech Republic, Northern Ireland, Norway, and England. The series acts as a bridge between disciplines and as a bridge between science and practice. Its focus is on all aspects of timetabling research and practice across personnel rostering, educational timetabling, sports scheduling and transportation timetabling. The conference in Son had over 90 delegates from all over the world. We had 4 plenary presentations, 49 standard talks, and 11 practitioner presentations. All the presenters were invited to submit revised papers to this special volume. Additionally, a public announcement was circulated

Integrated surface and departure management at airports by optimization

A key challenge in Air Traffic Management is to provide a swift flow of airplanes at and near the airports. The pressure on existing airports will be higher as demand of air transport is predicted to increase over the next decades. Airline companies compete on delivering improved departure and arrival punctuality for their flights. In this paper we present experimental results where we are comparing the performance of traditional tower control decisions versus decisions supported by optimization technology in a simulation environment. We present a mathematical model for the integrated departure management and surface management problem and a solution algorithm based on a heuristic decomposition of the integrated problem. This represents a first attempt to solve the two problems simultaneously. Our approach is designed for dynamic rescheduling and real-time environment, with corresponding response time requirements. Finally, we present computational results that show significant improvements in punctuality and reductions in taxi times.