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The two examples in Figure 3.7 and Figure 3.8 show only one DA is involved. However, Figure 3.9 shows the sequence of messages when more than one DA needs
drivers. In this scenario, three DAs DA1, DA2 and DAn need to find CAs that could take their duties. The matching process takes place in turn between all the DAs. It starts
with DA1, then DA2, and finally DAn. The matching process and message passing is the same as described before. The only difference is that the process takes longer. In
this example, CAn, CA2, and CA1 match DA1, DA2 and DAn respectively.
3.5 Summary
The main objective of this chapter is to present the proposed approach, which is an automated crew rescheduling system. Prior to that, the chapter presents some of the
issues relating to the proposed approach. Two issues are discussed first, whether to reschedule crew or reschedule crew schedules and second, whether to propose a
complete crew scheduling system or just make an addition to the current system. The research found that crew schedule rescheduling is not suitable for real time because of
the level of complexity associated with it. For example, when trying to conduct any rescheduling to crew schedules, schedulers need to consider the cost and time factors,
such as number of available crews, driving hours left for each one, and their location of every crew. These factors make it very difficult and not practical in the real world.
Thus, in this research we prefer crew rescheduling, which means that the schedules are still the same but changes are made in the duty assignment. The research also concludes
that an additional module is suitable for this research since the focus is on solving problems arising with UE that happen in everyday operation on crew schedules, and not
on finding optimum schedules. The chapter thereafter models the manual way of crew rescheduling, and, based on the models, it proposes the Crew Rescheduling System with
a MAS CRSMAS. Then CRSMAS is modelled with the concept of MAS. In CRSMAS architecture there are two types of agents: duty agent DA and crew agent
CA. CA represents a crew, and DA corresponds to a duty that needs to find a crew because the original crew is late or unavailable. The agent’s interactions are modelled
with sequence diagrams that show the types of messages passing between agents in different scenarios. For example, when a match is found, no match is found and
multiple matches take place. CRSMAS can be used to help supervisors in making quick
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decision relating to crew rescheduling whenever a crew is late or unavailable. The decision will not allow the violation of EC driving hour rules and will suggest the best
optimum solution within a short period of time within seconds or minutes. The next two chapters will test CRSMAS whether it achieves the research aim or not.
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Chapter Four: Single Event Experiments
4.1 Introduction
