EVALUATION OF UNCONSTRAINING METHODS IN AIRLINES’ REVENUE MANAGEMENT SYSTEMS

Airline revenue management systems are used to calculate booking limits on each fare class to maximize expected revenue for all future flight departures. Their performance depends critically on the forecasting module that uses historical data to project future quantities of demand. Those data are censored or constrained by the imposed booking limits and do not represent true demand since rejected requests are not recorded. Eight unconstraining methods that transform the censored data into more accurate estimates of actual historical demand ranging from naive methods such as discarding all censored observation, to complex, such as Expectation Maximization Algorithm and Projection Detruncation Algorithm, are analyzed and their accuracy is compared. Those methods are evaluated and tested on simulated data sets generated by ICE V2.0 software: first, the data sets that represent true demand were produced, then the aircraft capacity was reduced and EMSRb booking limits for every booking class were calculated. These limits constrained the original demand data at various points of the booking process and the corresponding censored data sets were obtained. The unconstrained methods were applied to the censored observations and the resulting unconstrained data were compared to the actual demand data and their performance was evaluated

Fragmentiranost europskog zračnog prostora: Procjena zasnovana na troškovnoj učinkovitosti

Due to the ANSPs’ (Air Navigation Service Providers’) unit rates variability in different European airspace areas, the AUs (Airspace Users) pay different financial amounts for the same ANS (Air Navigation Service) provision. The AUs’ interest is to achieve the lowest possible operational costs, so it is often the case that the aircraft, if there is an alternative, fly on longer but economically more acceptable routes through cheaper charging zones. Over the time, the application of such practice has led to the creation of different business interests – that is a critical issue hindering further air transport development in Europe. This paper investigates the research question of whether and if so, how the European airspace is fragmented in terms of cost-efficiency features. By the application of the spatial autocorrelation methodology, i.e. by associating every ANSP’s unit rate value with its spatial position within the European ATM (Air Traffic Management) system, the research question has been answered. Research findings indicate that the European airspace is fragmented from a cost-efficiency aspect and divided into several different homogeneous areas. Such areas are characterized by a certain similarity level of adjacent unit rates, whereas one charging zone represents a hotspot in terms of its dissimilarity to adjacent spatial units.Zbog varijabilnosti jediničnih cijena Pružatelja usluga u zračnoj plovidbi na različitim područjima europskog zračnog prostora, korisnici zračnog prostora za istu uslugu u zračnoj plovidbi plaćaju različite financijske iznose. Interes korisnika zračnog prostora je ostvariti što niže operativne troškove, pa je čest slučaj da zrakoplov, ukoliko postoji alternativa, leti dužim, ali ekonomski prihvatljivijim rutama kroz jeftinije naplatne zone. Tijekom vremena, primjena takve prakse dovela je do stvaranja različitih poslovnih interesa - što predstavlja kritični problem koji ometa daljnji razvoj zračnog prometa u Europi. Ovaj rad se bavi proučavanjem istraživačkog pitanja je li i ukoliko jest, kako je europski zračni prostor fragmentiran s aspekta troškovne učinkovitosti. Primjenom metodologije prostorne autokorelacije, tj. povezivanjem jediničnih cijena Pružatelja usluga u zračnoj plovidbi s njegovim prostornim položajem u okviru europskog sustava upravljanja zračnim prometom, dobiva se odgovor na postavljeno istraživačko pitanje. Rezultati istraživanja ukazuju da je europski zračni prostor fragmentiran s aspekta troškovne učinkovitosti i da je podijeljen u nekoliko različitih homogenih područja. Pri tom, takva područja karakterizirana su određenom razinom sličnosti susjednih jediničnih cijena, dok jedna naplatna zona predstavlja žarišno područje u smislu svoje neusklađenosti sa susjednim prostornim jedinicama

A Review of Ancillary Services Implementation in the Revenue Management Systems

Ancillary services in air transport represent a set of services provided to passengers to choose from, enabling them to enhance their travel experience while accumu-lating additional airline revenue. Low-cost airlines pi-oneered the practice, but the separation of ancillary services from the basic service has become an intense-ly growing trend in the air transport industry over the last decade. This practice has enabled low-cost airlines to significantly reduce the price of the basic service. To remain competitive in an era of transparency provided by search engines, traditional airlines offer ancillary ser-vices in addition to the basic service. To meet the passen-ger’s needs, a whole range of ancillary services has been created. However, existing revenue management systems do not take this ancillary revenue into account when cal-culating reservation limits. If the airline knew that an in-dividual passenger is willing to pay more for ancillary services, the system would be able to adjust the availabil-ity of the service for that passenger during the booking process. A review of research on passengers’ willingness to pay for ancillary services is presented in the paper, as well as a review on research on the personalisation of ancillary services and challenges of integrating person-alised pricing into existing revenue management systems

Zagreb Terminal Airspace Capacity Analysis

The paper deals with the Zagreb Terminal Airspace capacity. The basic scenario has been modelled using the RAMSPlus simulator and capacity has been calculated by using the WMSE method which takes into account the peak-hour workload based on air traffic controllers’ tasks. The problem of traffic congestion has been analyzed and several case study scenarios have been simulated. The conducted simulations have demonstrated that in the conditions of increased traffic loads (traffic demand amounting to 6% annually) the working technology and the airspace organization of Zagreb Terminal Airspace will become a restricting factor at peak-hour workloads. The new technologies in Zagreb Terminal Airspace (P-RNAV routes and airspace sectorization) will enable the reduction in air-traffic controller’s workload regarding radar vectoring, radio-telephony and coordination tasks. This should increase the airspace capacity and thus enhance the safety and orderly flow of air traffic. KEY WORDS: terminal airspace, capacity, simulation, workload, task, sectorizatio

Delay Causes Distribution: EU vs Croatian Coastal Airports

The growth in air traffic in recent decades in Europe has consequently caused aircraft delays due to insufficient capacities of airspace and airports. Primary and reactionary delays at certain European and Croatian coastal airports in 2014 are analyzed in the paper according to CODA methodology and classified according to main flight delays causes. The largest share of delay minutes at the Croatian coastal airports (75%) are related to reactionary delays, ranging from around 20% to 60% of total delay at the most congested European airports. Special emphasis is given to the analyses of rotational reactionary delay, and the results indicate that the share of reactionary delay in total delay at the Split airport is significantly higher compared to selected European airports, which may be explained by delays propagated from air traffic network and limited airport capacity. The total recorded delay at Croatian coastal airports is minor compared to total recorded delay in the European air traffic system, but delay patterns are quite similar, especially during peak summer months

A Comparative Analysis of Baggage Irregularities at Zagreb Airport

Global air traffic has been recording a growing passengernumber accompanied by the growth of lost and mishandledbaggage on final destinations. Airlines are facing cost-risingconsequences that lead to additional problems in global lATAtrends to simplify the business and cost reduction policy in theIndustry. The World Tracer program, developed for mishandledbaggage, based on simplicity and optimal costs has done alot to improve baggage tracing. Supported by SITA and lATA,the program has been created to meet the needs of airlines andground handling partners. The Program team leaders a re workingon improving the tracing procedure to catch up with thegrowing mishandled baggage problem. The paper examines theissues related to lost, delayed or pilfered baggage worldwide andespecially at Zagreb Ai1port. Zagreb Airport is the World TraceManagement subscriber with its Lost and Found office as aProgram user. The annual office statistics clearly point to therise of mishandled and lost baggage, thus being well suited forthe global problem of the growth

AIR TRANSPORT MARKET CHALLENGES IN THE SOUTHEAST EUROPE

Air transport industry is one of the very important businesses worldwide. The global recession in the years 2008/2009 and regional economic crisis in the countries of Southeast Europe have caused domestic demand weakening for air travel. At the same time, high increase of competition on the air transport market in the period 2008-2016 made positive influence on flows of people, goods, capital, technology and ideas. State of the economy and air transport industry in the Southeast Europe countries has been analyzed in all-important segments including airlines, airports and air navigation services. Air transport regional market is still undeveloped with relatively weak connections within the region. Financial achievements for selected dominant airlines in the Southeast Europe region are showing negative result and questionable sustainability of the business models in the future. Analysis of air transport infrastructure within the Southeast Europe region shows relatively low level of performance indicators compared to 136 countries worldwide in the year 2017. Implementation of different restructuring measures and strategy improvements are necessary for the future surviving perspective of air transport Southeast Europe regional market