A new methodology for automatic process planning and execution based on adaptive information modeling

This research has developed methods to automate the generation of process plans for machining operations. The generated process plans are flexible and may vary with the capability of the available manufacturing facilities and the desired production criteria. The finished part and raw part are represented in boundary representation, a solid modeling scheme. The input of the proposed system framework includes the description of (1) the raw part, (2) the finished part, (3) the available cutters, (4) the available machine tools, and (5) the desired production criteria. From the provided input, the proposed approach can automatically, without any human intervention, select the cutter approach directions, cutters, and generate NC paths to machine the raw part into the finished part. To generate the flexible process plans, a new concept of process requirement for manufacturing the finished part is proposed. This process requirement describes the set of acceptable cutter approach directions; and for each acceptable cutter approach direction, it describes the range of acceptable cutters to manufacture the finished part

A Hit-Rate Based Dispatching Rule For Semiconductor Manufacturing

Hit-rate, the percentage of on-time completion, is a very important performance measure in a make-to-order semiconductor fab. This paper presents a dispatching algorithm for such a fab with machine-dedication feature. This feature imposes a constraint on the production route due to the advance of manufacturing technology, and has been rarely addressed in previous literature. A dispatching algorithm, called LBSA, was recently developed for a fab with machine-dedication feature. The LBSA algorithm outperformed many other dispatching methods in terms of hit-rate for short-routing products but not so well for long-routing products. This paper develops a dispatching method that shows a high hit-rate performance for both short-routing and long-routing products

A Modified Lotka–Volterra Model for Diffusion and Substitution of Multigeneration DRAM Processing Technologies

We attempt to develop an effective forecasting model for the diffusion and substitution of multigeneration Dynamic Random Access Memory (DRAM) processing technologies. We consider market share data and propose a modified Lotka–Volterra model, in which an additional constraint on the summation of market share is introduced. The mean absolute error is used to measure the accuracy of our market share predictions. Market share data in DRAM industries from quarter one (Q1) of 2005 to 2013 Q4 is collected to validate the prediction accuracy. Our model significantly outperforms other benchmark forecasting models of both revenue and market share data, including the Bass and Lotka–Volterra models. Compared to prior studies on forecasting the diffusion and substitution of multigeneration technologies, our model has two new perspectives: (1) allowing undetermined number of multigeneration technologies and inconsecutive adoption of new technologies and (2) requiring less data for forecasting newborn technologies

Scheduling a hybrid MTO/MTS semiconductor fab with machine-dedication features

A semiconductor foundry is essentially a make-to-order (MTO) factory. Yet, in a low-demand season, it may enter into a hybrid business model--producing make-to-stock (MTS) as well as MTO products to maintain high utilization of machines. This research proposes a scheduling method for such a hybrid MTO/MTS system with machine-dedication characteristics, a constraint imposed on the process route caused by the advance of manufacturing technology. The scheduling method aims to achieve a high on-time delivery rate for MTO products as well as a high throughput for MTS products. Simulation experiments show that the proposed scheduling method outperforms representative methods in the literature.