This report describes a Logistics Management Systems design project that is performed at KLM Aircraft Services (AS). AS is the part of KLM that is responsible for a large portion of the tasks that must be done to an aircraft that has landed and has to be used again. When an aircraft has landed the resources that are required to service the aircraft should be available. Getting a resource available has a certain lead time and the availability of resources is not infinite. To guarantee the availability of resources a planning must be made. At KLM AS this planning is done in the PRI chain. The basis for the activities in this chain is the timetable. The current PRI chain evolved from practice; on the basis of experiences the chain has originated. Modifications to the chain are made also on the basis of experiences and observations. AS had the feeling that the chain that is currently in place is not functioning optimally. The goal of this assignment was to make a new, ideal PRI chain, preferable derived from a generic chain that has been described in literature, that would result in a better performance of AS. Deriving a generic planning chain from literature was not possible because the chains that have been described in literature are per definition made for a specific situation. Because this was not possible a new PRI chain has to be designed. The new chain that has to be designed should be suitable for the planning problem that AS faces. A danger when making a new chain for the same problem as the current chain, is that the new chain will be very similar to the old chain. To overcome this danger, a constraint approach has been chosen. This means that the constraints that lie on the basis of AS's processes are taken as building blocks for the new chain. A constraint is an artifact that cannot be changed within the scope of this project. The constraints are identified by analyzing current processes, not the choices that AS has already made in the current chain. Based on the constraints, the ideal PRI chain has been described. The new chain describes for AS on what moments in time they have to make a decision. The timing of the decision is based on the constraints that were formulated to be sure that the decision is made in time. The new chain describes for both employee and equipment planning when to make what decision. For some decisions, guidelines are given about subjects that should be taken into account when making the decision. The new PRI chain contains stepwise decisions to be sure that sufficient employees and equipment are available on the day of operation. As the lead time for equipment is longer than for employees, the first step is to determine the required equipment one year ahead. The lead time for buying new equipment is one year, so new equipment is available when it is needed when the buying decision is made one year ahead. The decision whether or not to buy new equipment is based on a forecasted performance model. This model incorporates a forecasted timetable and determines the forecasted performance. Having more equipment available will increase the costs for equipment but will also increase the performance with less non-performance costs as a result. The model can be used to make a financially grounded decision about whether or not to acquire additional equipment. The second step is to make sure that sufficient employees with the right classifications are available. The same model as described above can be used for this purpose. For employees it is very important that a decision is made about the number of KLM employees and the number of flexible employees that is used. The third step of the new PRI chain uses the outcome of the first two steps. At the moment that this step is done, no adjustments on the available equipment and KLM employees can be made anymore. The number of flexible employees that is used can still be changed. In this step, actual information about the timetable is used to determine for every moment on the day of operation the need for equipment and employees. The availability of employees is bounded by CAO constraints. Therefore a planning is made in advance of the day of operation that tells how many employees of what kind are required for different moments of the day. By changing the number of flexible employees that is used shortly before the day of operation, the actual available employees are aligned with the planned number of employees that must be available. The design for the new PRI chain has been compared to the current PRI chain. This analysis revealed that the feeling that AS has about the non-optimal performance of the current PRI chain was true. In the current chain decisions about the required number of employees or the required amount of equipment are made too late or a made without having the required information. Because decisions are made too late or are based on too less information, capacity adjustments are not ready in time or are not in line with actual demand. This will have a negative effect on the performance of AS. This report ends with a set of recommendations to improve the current PRI chain, based on differences with the ideal PRI chain. The recommendations vary on the effort that is required to complete them, the effect they have and the moment in time when they can be fulfilled. The recommendations have been ordered graphically to give AS guidelines about what recommendation to start with. Implementing these recommendations will lead to a PRI chain that will perform better. The costs for executing all steps in the PRI chain will stay about the same.
|Qualification||Doctor of Philosophy|
|Award date||1 Jan 2010|
|Place of Publication||Eindhoven|
|Publication status||Published - 2010|