A simulation scenario based mixed integer programming approach to airline reserve crew scheduling under uncertainty

The environment in which airlines operate is uncertain for many reasons, for example due to the effects of weather, traffic or crew unavailability (due to delay or sickness). This work focuses on airline reserve crew scheduling under crew absence uncertainty and delay for an airline operating a single hub and spoke network. Reserve crew can be used to cover absent crew or delayed connecting crew. A fixed number of reserve crew are available for scheduling and each requires a daily standby duty start time. This work proposes a mixed integer programming approach to scheduling the airline’s reserve crew. A simulation of the airline’s operations with stochastic journey time and crew absence inputs (without reserve crew) is used to generate input disruption scenarios for the mixed integer programming simulation scenario model (MIPSSM) formulation. Each disruption scenario corresponds to a record of all of the disruptions that may occur on the day of operation which are solvable by using reserve crew. A set of disruption scenarios form the input of the MIPSSM formulation, which has the objective of finding the reserve crew schedule that minimises the overall level of disruption over the set of input scenarios. Additionally, modifications of the MIPSSM are explored, a heuristic solution approach and a reserve use policy derived from the MIPSSM are introduced. A heuristic based on the proposed MIPSSM outperforms a range of alternative approaches. The heuristic solution approach suggests that including the right disruption scenarios is as important as the quantity of disruption scenarios that are added to the MIPSSM. An investigation into what makes a good set of scenarios is also presented

Система управления знаниями и цифровая трансформация компании

The article considers the different approaches towards modelling and implementation of knowledge management systems in the context of the enterprise’s digital transformation. The methodology is based on the conceptualization of the domain using Semantic Web technologies, i.e. OWL and SPARQL standards, and semantic reasoners. The purpose of this paper is to present the results of knowledge management (KM) system design. Semanticbased architecture of search engine is proposed as an instrument for strict searching and corporate knowledge exploration. The KM-system deployment is supposed to be as a checkpoint of digital transformation of a company which means that the company is eager to earn money from data considered as an asset. As a whole the advantages of ontology-based KM-system are: minimizing the mistakes made by the employees; fast adaptation and involving the employees recently hired by the company; improving the speed and quality of analytics in company; preserving the knowledge which could be lost because of staff retirement