Crew scheduling: Difference between revisions

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'''Crew scheduling''' is the process of assigning crews to operate transportation systems, such as rail lines or aircraft[[airlines]].<ref>{{cite journal |last1=Pang |first1=Shinsiong |title=Optimize railway crew scheduling by using modified bacterial foraging algorithm |journal=Computers & Industrial Engineering |date=5 April 2023 |volume=180 |issue=180 |page=109218 |doi=10.1016/j.cie.2023.109218 |s2cid=257990456 }}</ref>

== Complex ==

Most transportation systems use software to manage the crew scheduling process. Crew scheduling becomes more and more complex as you add variables to the problem. These variables can be as simple as 1 ___location, 1 skill requirement, 1 shift of work and 1 set roster of people. In the Transportation industries, such as Rail or mainly Air Travel, these variables become very complex. In Air Travel for instance, there are numerous rules or "constraints" that are introduced. These mainly deal with legalities relating to work shifts and time, and a crew membersmember's qualifications for working on a particular aircraft. Add numerous locations to the equation and Collective Bargaining and Federal labor laws and these become new considerations for the problem solving method. Fuel is also a major consideration as aircraft and other vehicles require a lot of costly fuel to operate. Finding the most efficient route and staffing it with properly qualified personnel is a critical financial consideration. The same applies to rail travel. Crew scheduling involves assigning complementary crews for each scheduled trip based on the timetable for the next day or a short period.<ref>Pang, S., & Chen, M. C. (2023). Optimize railway crew scheduling by using modified bacterial foraging algorithm. ''Computers & Industrial Engineering'', ''180'', 109218.</ref> In rail transportation, crew scheduling involves generating crew duties for conductors and train operators.<ref>{{Cite journal |last1=Pang |first1=Shinsiong |last2=Chen |first2=Mu-Chen |date=June 2023 |title=Optimize railway crew scheduling by using modified bacterial foraging algorithm |url=http://dx.doi.org/10.1016/j.cie.2023.109218 |journal=Computers & Industrial Engineering |volume=180 |pages=109218 |doi=10.1016/j.cie.2023.109218 |issn=0360-8352|url-access=subscription }}</ref>

The problem is computationally difficult and there are competing mathematical methods of solving the problem. Although not easy to describe in one sentence, the goal is the essentially the same for any method of attacking the problem:<br>

'''"Within a set of constraints and rules, move a set roster of people with certain qualifications, from place to place with the least amount offewest personnel and aircraft or vehicles in the least amount of time.'''" <br>Lowest cost has traditionally been the major driver for any crew scheduling solution.

== 4Four Parts ==

The problem is computationally difficult and there are competing mathematical methods of solving the problem. Although not easy to describe in one sentence, the goal is the essentially same for any method of attacking the problem:<br>

Although not a "rule", We can describe at least 4four parts of the equation that are ingested by the computational process:

'''Within a set of constraints and rules, move a set roster of people with certain qualifications, from place to place with the least amount of personnel and aircraft or vehicles in the least amount of time.''' <br>

Lowest cost has traditionally been the major driver for any crew scheduling solution.

== 4 Parts ==

Although not a "rule", We can describe at least 4 parts of the equation that are ingested by the computational process:

* People and their qualifications and abilities.

* Aircraft or vehicles and their "People" qualification requirements and their cost to operate over distance.

* Locations and the time and distance between each ___location.

* Work rules for the personnel, including Shift hours and seniority.

<br>

In crew scheduling the rules and constraints are typically a combination of:

* government regulations concerning flight time, duty time and required rest, designed to promote [[aviation safety]] and limit [[crewpilot fatigue]],

* crew bid requests, vacations,

* [[labor agreements]]

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* returning crew to their base at the end of their trip (called [[Deadheading (aviation)|deadheading]])

The first phase in crew planning is building the crew pairings (also known as trips, rotations, among other popular descriptions). This process pairs a generic crew member with a flight so that at the end of this process all aircraft flights are covered and all trips (combination of flights starting at a crew base and returning to that crew base or co-terminal are crew legal. The next step is the allocation of those trips to the individual crewmember.

All of these issues need to be addressed in order to create a satisfactory solution for personnel and management of the organization. For the Crew member in a seniority based system schedules are decided largely on workplace seniority. Those at the top of a seniority list are allowed some choices. As assignments are made and the remaining roster of personnel becomes fewer, managements' systems start to assign the remaining trips based on a weighting of the 4 previously mentioned variables, without any input from personnel.<br>

This does not allow the personnel to have any choice or voice in the schedules they receive. This lack of scheduling awareness until the end of each scheduling period is a major workforce issue and an employee [http://www.time.com/time/business/article/0,8599,1997688,00.html morale problem], often creating a tenuous situation especially where a collective bargaining agreement is in place, and particularly at negotiation time. To address this issue, and to satisfy the growing voice of personnel to have a say in their schedules, in the 1970s the company SBS International, led by Mr. Christian Boegner, created the concept of a Preferential Bidding System (PBS).

This was a new method of allowing personnel to create input data that factored in the calculations of the schedules, while still allowing management a level of control over critical business decisions. This has become a standard in the industry. The newest approach to PBS and crew scheduling takes advantage of the interaction possible via the web, which wasn't possible in the 1970s.<ref>http://www.crewingsolutions.com/sites/all/files/resources/SP-WhitePaperPBS.pdf</ref>

For the US, Canada and Australia, seniority generally rules. The two processes (which are completely different) are referred to as bid lines and preferential bidding. In seniority order, pilots bid for either a line of time (bidline) or trips and days off (preferential bidding. These are awarded based on seniority and modified only when their selections have already been taken by a more senior crew member (bidlines) or their trip and day off selections (preferential bidding) do not make up a complete line (hours, days off, etc. parameters agreed to by the company and the union). The senior folks have more time off, better choice of time off and fly better trips than the junior crew members, generally speaking. In the US, this is considered fair.

== Real Time ==

Crew members and management can interact with schedules and data in a real-time web interface. Status can be seen and acted upon as it develops and changes, rather than requesting or bidding for a schedule once, then waiting to see the outcome. Although that advance itself was revolutionary at the time [[Preferential bidding system|Mr. Boegner developed the mathematical algorithm to do so]], interactive live PBS crew scheduling is the next step. The internet and its reach are starting to change crew scheduling within the large, global organizations that use it.<ref>http://www.carmensystems.com/research_development/articles/crtr0303.pdf "Solving the World's Largest Crew Scheduling Problem"</ref>

For European airlines and other airlines in the rest of the world, the allocation process is completely different. The company builds the pilot schedules directly to meet their needs, not the pilot's needs. Before assigning a single trip, the schedulers put all planned absences (vacation, training, etc.) onto the crew members' schedule. Only then are trips assigned to the individual crew members. As such, fairness means that the most senior captain and the most junior captain have the same amount of duty time, block hours, night time, time away from base, layovers, expense pay, etc. in a given schedule period. Seniority is out and all work is completely homogenized. For them, anything else is unfair, undemocratic. Slowly over the last thirty years, foreign airlines using the "no seniority" rostering system have allowed some measure of seniority to creep into the allocation process from pilots who may now ask for a specific day off or trip once a quarter or make multiple requests within a schedule period. Although this may sound very much like preferential bidding, it is not. The disparity between junior and senior crew members is still very limited and thus achievement of your choices is limited.

== Disruptions ==

Additional unplanned disruptions in schedules due to weather, maintenance, and [[air traffic control]] delays can disrupt schedules, so crew scheduling software remains an area for ongoing research.<ref>http://www.engr.pitt.edu/~schaefer/Papers/UncertainCrewSched.pdf {{Webarchive|url=https://web.archive.org/web/20070612154016/http://www.engr.pitt.edu/~schaefer/Papers/UncertainCrewSched.pdf |date=2007-06-12 }} "[[Airline crew]] Scheduling under Uncertainty"</ref>

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== RelatedSee topics (systems)also ==

* [[Preferential bidding system]]

* [[Fatigue (safety)]]

* [[Automated planning and scheduling]]

== Related topics (algorithms and software) ==

* [[Linear programming]]

* [[Column generation]]

* [[TabuDriver searchscheduling problem]]

* [[Fatigue Avoidance Scheduling Tool]]

* [[Fatigue (safety)]]

* [[Linear programming]]

== List of a few crew scheduling software vendors ==

* [[Preferential bidding system]]

* [[ADTabu OPT, division of Kronossearch]]

* [[Aircraft Information Management System|AIMS]], Aircraft Information Management System

* [http://www.aos.us/ AOS, Advanced Optimization Systems]

* [[Jeppesen]] Carmensystems

* [[Lufthansa Systems]]

* [http://navitaire.com/ Navitaire]

* [http://www.navtech.aero/ Navtech]

* [[Sabre Airline Solutions]]

* [[SISCOG]]

* [[Universal Weather and Aviation]]

* [http://www.giro.ca/en/products/hastus GIRO (HASTUS)]

* [http://www.kernel-software.com Kernel-Software]

== References ==

{{reflist}}

== Further reading ==

[[Category:Air safety]]

* {{cite news |url= https://airwaysmag.com/industry/solving-the-nightmare-of-crew-scheduling/ |title= Solving The Nightmare Of Crew Scheduling |date= January 17, 2019 |work= Airways Mag |author= Alex Osleger}}

[[Category:Aviation terminology]]

[[Category:Optimization algorithms]]

[[Category:AirAviation safety]]

[[Category:AviationFlight terminologyplanning]]

[[Category:Optimization algorithms and methods]]

[[Category:Transportation planning]]

[[Category:Transport safety]]

[[Category:Scheduling (transportation)]]