Abdul Hakim Halim

A maintenance service contract for a warranted product

In this paper, we investigate a maintenance service contract for a warranted product carried out by the Original Equipment Manufacturer (OEM). The model was developed under the assumption that there are one consumer and one service provider who is the OEM. This is typically applied to the situation where the OEM is the only service provider such as in the mining industry. From the OEM point of view, two contract options were considered, they are: the OEM carried out all repairs and preventive maintenance activities; the OEM carries out failure and the customer undertakes in house preventive maintenance actions. The model uses a non-cooperative game formulation by maximizing expected profits. We use a linear function of failure intensity to consider a product with increasing failure intensity. We obtain the pricing structure in the contract. And for the customer, they can choose the optimal option under the term of contract.

A batch scheduling model for m heterogeneous batch processor

This research addresses a batch scheduling problem for single item parts with multi due date on m heterogeneous batch processors. The objective is to minimise total actual flowtime of parts through the shop. The total actual flowtime of parts in a batch is the multiplication of the interval between batch arrival time and the due date by the number of parts in the batch. Using the actual flowtime as the objective means it is oriented to satisfy the due date as a commitment to customers, and simultaneously to minimise the length of time of the parts spending in the shop. An algorithm to solve this problem is proposed.

An Object-Oriented Modelling of Production Scheduling for Flexible Manufacturing System

This paper presents an object-oriented modelling approach to production scheduling for FMS. The purpose of this study is to prepare a simulation tool to try a method of production scheduling that allocates jobs to the machines and cutting tools in an FMS. This model is developed by using Pharo as the language software for object-oriented programming through UML system design. This model consists of three types of classes. The first type is the Equipment-class, which related to the physical equipment in the FMS, for example machining-centers, cutting tools, pallet stocker, stacker crane. The second type is the Product-class that related to the information how to process the product. This class has sub-class such as process plan, machining operation and required cutting tools. The third class is the Production Planning and Controlling (PPC) class, which related to create the schedule to equipment. The PPC-class has sub-classes such as the daily order or job, job sequence, job allocation on machine and scheduling methods. A numerical example is provided in this paper to show that the object-oriented model for FMS and production scheduling is verified. The FMS consist of four identical machining centers and eight jobs. Each job has a process plan that requires some specific cutting tool types. The method for production scheduling in this model is Shortest Processing Time (SPT). The production scheduling performance is measured in this model.

Joint economic lot size model with quality improvement for a single supplier and a single buyer cooperative collaboration

This paper explores the impact of quality improvement on joint economic lot size (JELS) models. It begins with the individual optimality of a supplier, which makes the deliveries during the production period, as soon as the quantity is equal to the batch size. The individual optimality of the buyer is based on the Economics Order Quantity (EOQ) model, whereas the supplier is based on the Economic Manufacturing Quantity (EMQ). A cooperative collaboration is stated based on a long-term agreement for sharing information. The result of the study shows that the JELS with quality improvement will provide smaller sub-lot sizes and lower joint total cost of 2.25% compares to the JELS without quality improvement. The purpose of quality improvement is to increase the proportion of conforming items. The result shows this proportion can only be improved under 0.879 and this value depends on the parameters in the investment function.

Production and delivery batch scheduling with a common due date and multiple vehicles to minimize total cost

This paper studies production and delivery batch scheduling problems for a single- supplier-to-a-single-manufacturer case, with multiple capacitated vehicles wherein different holding costs between in-process and completed parts are allowed. In the problem, the parts of a single item are first batched,then the resulting batches are processed on a single machine. All completed batches are transported in a number of deliveries in order to be received at a common due date. The objective is to find the integrated schedule of production and delivery batches so as to satisfy its due date and to minimize the total cost of associated in-process parts inventory, completed parts inventory and delivery. It should be noted that both holding costs constitute a derivation of the so-called actual flow time, and the delivery cost is proportional to the required number of deliveries. The problem can be formulated as an integer non-linier programming and it is solved optimally by Lingo 11.0 software. Numerical experiences show that there are two patterns of batch sizes affected by the ratio of holding costs of in-process and completed parts. It can be used by practitioners to solve the realistic integrated production and delivery batch scheduling problem.

An FMS Dynamic Production Scheduling Algorithm Considering Cutting Tool Failure and Cutting Tool Life

This paper deals with Flexible Manufacturing System (FMS) production rescheduling due to unavailability of cutting tools caused either of cutting tool failure or life time limit. The FMS consists of parallel identical machines integrated with an automatic material handling system and it runs fully automatically. Each machine has a same cutting tool configuration that consists of different geometrical cutting tool types on each tool magazine. The job usually takes two stages. Each stage has sequential operations allocated to machines considering the cutting tool life. In the real situation, the cutting tool can fail before the cutting tool life is reached. The objective in this paper is to develop a dynamic scheduling algorithm when a cutting tool is broken during unmanned and a rescheduling needed. The algorithm consists of four steps. The first step is generating initial schedule, the second step is determination the cutting tool failure time, the third step is determination of system status at cutting tool failure time and the fourth step is the rescheduling for unfinished jobs. The approaches to solve the problem are complete-reactive scheduling and robust-proactive scheduling. The new schedules result differences starting time and completion time of each operations from the initial schedule.

Model Penjadwalan Batch Multi Item dengan Dependent Processing Time

This paper investigates a development of single machine batch scheduling for multi items with dependent processing time. The batch scheduling problem is to determine simultaneously number of batch ( ), which item and its size allocated for each batch, and processing sequences of resulting batches. We use total actual flow time as the objective of schedule performance. The multi item batch scheduling problem could be formulated into a biner-integer nonlinear programming model because the number of batch should be in integer value, the allocation of items to resulting batch need binary values, and also there are some nonlinearity on objective function and constraint due to the dependent processing time. By applying relaxation on the decision variable of number of batch ( ) as parameter, a heuristic procedure could be applied to find solution of the single machine batch scheduling problem for multi items.