The solution must be as efficient as possible while respecting crew member preferences, honoring seniority, conforming regulations, and operation coverage requirements.
The monthly schedule called "line" which a crew member gets will consist of a series of "pairings".
Each month the airlines crew planning sets the new pairings due to new locations being added or removed, new times, or changes in aircraft.
Though management is eager to streamline operations, crew members may still prefer the bid lines.
PBS provides a one-step process from the pairings to the lines that each crew member prefers and can legally cover.
The real challenge for PBS is that it tries to solve two innately conflicted goals, honoring preferences without violating seniority and awarding all pairings.
In a conventional PBS, crew members make their bids and chooses their preferences based upon their own best interests.
The application was developed by SBS founder Christian Boegner who later founded Crewing Solutions, and was in use on powerful internal computers at TWA among other airlines.
With the advent of increasingly more powerful airline and home computers as well as high speed internet connectivity having become ubiquitous and mainstream, those original computerized programs have evolved into today's web-based, with crew members using laptop computers or even mobile devices to bid.
The conventional PBS process can now be fully interactive, affording the possibility that more crew members get a schedule that fulfills their wishes.