Integrated Airline Crew Pairing and Crew Assignment by Dynamic Constraint Aggregation

Abstract

Traditionally, the airline crew scheduling problem has been decomposed into a crew pairing problem and a crew assignment problem, both of which are solved sequentially. The first consists of generating a set of least-cost crew pairings (sequences of flights starting and ending at the same crew base) that cover all flights. The second aims at finding monthly schedules (sequences of pairings) for crew members that cover all pairings previously built. Pairing and schedule construction must respect all safety and collective agreement rules. In this paper, we focus on the pilot crew scheduling problem in a bidline context where anonymous schedules must be built for pilots and high fixed costs are considered to minimize the number of scheduled pilots. We propose a model that completely integrates the crew pairing and crew assignment problems, and we develop a combined column generation/dynamic constraint aggregation method for solving them. Computational results on real-life data show that integrating crew pairing and crew assignment can yield significant savings—on average, 3.37% on the total cost and 5.54% on the number of schedules for the 7 tested instances. The integrated approach, however, requires much higher computational times than the sequential approach.

Cascading Delay Risk of Airline Workforce Deployments with Crew Pairing and Schedule Optimization

“…A crew itinerary is called pairing, which is constructed by a set of duties, consisting of a number of flights, with sit time and rest period in between as needed, according to the regulations . CAP is to find a monthly schedule that covers all the pairing found in CPP, which is usually formulated as a set partitioning problems and solved by using the column generation approach . The difficulty of using column generation is the handling of a huge number of column and constraint matrices in the master problem when the problem scale grows larger .…”

“…Until now, column generation is still the main approach in solving CPP. Saddoune et al . applied the column generation approach with the dynamic constraint aggregation technique to solve integrated crew pairing and crew assignment problems.…”

Modelagem integrada do problema de programação de tripulantes de aeronaves.

“…Cacchiani e Salazar-González (2013), e Salazar-González (2013) integraram a solução da atribuição de frota, da atribuição de aeronaves e da determinação de viagens (Etapas 2, 3 e 4). Guo et al (2006), Zeghal e Minoux (2006), Souai e Teghem (2009), Gomes (2009) e Saddoune et al (2011) adotaram metodologias para a solução integrada da programação de tripulantes (Etapas 4 e 5).…”

“…As estratégias para modelagem integrada do PPT ainda são escassas na literatura. Nas subseções a seguir são apresentados os principais trabalhos desta linha de pesquisa: Guo et al (2006), Zeghal e Minoux (2006), Souai e Teghem (2009), Gomes (2009), Gomes e Gualda (2011), e Saddoune et al (2011).…”

“…Tal simplificação não representa uma modelagem integrada para o PPT, dado que podem surgir conflitos durante a atribuição de escalas aos tripulantes em uma fase posterior, conforme observado emZeghal e Minoux (2006),Souai e Teghem (2009) eGomes (2009). Os autores também não especificaram como as escalas viáveis foram geradas Saddoune et al (2011). consideraram 4 variantes do método de agregação bi-…”