Chikong Huang

Optimal burn-in time and warranty length under fully renewing combination free replacement and pro-rata warranty

Abstract Warranty is an important factor of marketing products; however, warranty always involves additional costs to the seller and these costs usually depend on product reliability. Burn-in is considered as a part of the production process in which the manufactured products are operated under accelerated stresses for a short time period before their release and has been applied as a way for enhancing product reliability. In the present paper, a cost model is developed to determine the optimal burn-in time and warranty length for non-repairable products under the fully renewing combination free replacement and pro-rata warranty (FRW/PRW) policy. Denoting w as the warranty length of the product, under the FRW/PRW policy, the seller agrees to replace the product that fails prior to the time point w′, where w′

Lean Production Implement Model for Aerospace Manufacturing Suppliers

Aerospace industry is a value-added and technology integrated industry. The aerospace manufacturing suppliers have to coordinate the demand of quality, delivery, cost and flexibility of aircraft to achieve customer satisfaction. This study integrates the lean concepts and summaries the Lean Cycle for lean implement and practice, and also develops the Lean Production Implement Model to strengthen the competitiveness of the manufacturing suppliers in the aerospace market.

Process control for aerospace chemical milling process

Aerospace industry is a value-added and technology integrated industry. Chemical milling process uses chemical solution to etch and remove the redundant material of detail parts to achieve the purpose of lightweight. The chemical milling usually proceeds after forming and prior to surface treatment. Due to the etching rate of chemical solution decays gradually after processing the detail parts for a period of time, so new solution needs to replenish periodically to compensate the solution decay of etching rate. This study analyses the characteristics of chemical milling process and constructs a suitable control chart to monitor the etching rate. By observing the trend of control chart, the replenish period of new solution can be determined.

Simulation and Analysis for Layout of Aerospace Sheet Metal Process with Lean Concept

Aerospace industry is a value-added and technology integrated industry. Sheet metal parts are important portion of aerostructures. The sheet metal production line combines five different routing types together. This study tries to make a comparison between job shop layout and cellular layout with lean concept. According to precedence diagram of sheet metal fabrication process, the model and measurement indicators can be constructed. The simulation software SIMPROCESS is then used to simulate the real-world cases under dynamic conditions. After the verification and validation process, we analyze the results that collected by simulation and provide the suggestions for the layout of aerospace sheet metal process.

Bottleneck Monitoring and Resource Allocation of Aerospace Sheet Metal Shop

Aerospace industry is a value-added and technology integrated industry. Sheet metal parts are important portion of aerostructures. The sheet metal production line combines five different routing types together. This study introduces an indicator to identify and monitor bottleneck among work centers, then develops an algorithm to reallocate the resources of sheet metal shop. It helps to construct a balance production line and satisfy the dynamic demand of aerospace market.

The Construction of Production Improvement Model for Aerospace Manufacturing Suppliers

Aerospace industry is a value-added and technology integrated industry. Due to the investment of aerospace industry is high and the pay back period is long, the type of aircraft production belongs to make-to-order system. Business flows and process flows are complex inside the aerospace manufacturing industry. Quality, cost, delivery and flexibility are the fundamental requirements of aerospace manufacturing suppliers. The aerospace manufacturing suppliers have to coordinate those fundamental requirements and construct the model of production system with Continuous Improvement in the competitive market. This study integrates the concepts of Six Sigma, Theory of Constraint, Lean Production and Value Engineering, and allies the functional groups and system resources inside the aerospace manufacturing suppliers. Then develop the Production Improvement Model with Continuous Improvement to allocate the resources to construct a production system. Thereby, the aerospace manufacturing suppliers can strengthen the competitiveness in the dynamic aerospace market.

Vehicle Routing Problem with Simultaneous Pickup and Delivery in Cross-Docking Environment

 Abstract—This study will discuss the vehicle routing problem with simultaneous pickup and delivery in a cross-docking environment. The transportation system includes three stages: (1) pickup goods, (2) delivery goods and pickup returned goods, and (3) delivery all returned goods. In the second stage, some operations of stage (3) may be accepted if time and loading capacity are available. We believe this special design can further reduce the transportation cost. A mathematical model is developed. The objective of this model is to minimize overall transportation cost including the vehicle transportation cost and the fixed cost of each route. An appropriate heuristic algorithm for solving the problem is also developed by using Tabu logic. Result of numerical example indicates that the proposed three-stage transportation system and heuristic algorithm can solve the vehicle routing problem effectively and efficiently.

The Curing Cycle Grouping of Aerospace Composite Shop

The production environment of aerospace industry is make-to-order. Aircraft parts should have higher precision and lightweight to achieve the requirements of safety, payload, and controllability. The composite part has become more important, profitable and value-added in aircraft industry. The main processes of composite parts are prepreg cutting, lay-up, autoclave curing, hand routing and painting. Due to the aerospace composite shop is mixed production line, the parts belong to different customers/ projects that have their own raw materials and curing cycles. The integration of resources from upstream to downstream to meet the demand of each customer/project is critical to shop floor control of composite shop. The purpose of this study is aimed to construct the grouping of curing cycles to simplify the complexity of different customers/ projects, harmonize the production rhythm of all work centers. It is believed that this study can increase the competitive advantages of composite shop in the global aerospace market.

Order picking algorithms for a two-carousel-single-crane automated storage and retrieval system

In practice, automated storage and retrieval carousel systems access orders through a first-come, first-served basis requires a longer storage and retrieval period with cleavage for reducing order access time. We developed a single-command mathematical model of a two-carousel-single-crane system based on storage and retrieval issues of they two-carousel-single-crane automated storage and retrieval system. Furthermore, based on these features, we developed a heuristic method to decide the sequence of storage and retrieval for both the single-layer-single-crane and two-carousel stages to design the final storage and retrieval operations of the two-crane-single-crane system. The researchers conducted a process to determine the operation with the shortest storage and retrieval sequence, which was then compared to a simulated annealing process to identify their advantages and disadvantages.

Shop Floor Control Mechanism of Aerospace Machine Shop

The production environment of aerospace industry is make-to-order. The life cycle of aircraft is more than 20 years. Aircraft parts should have higher precision and lightweight to achieve the requirements of safety, payload, and controllability. Machine parts are the important portion of aero-structures. Base on the strength, function, contour of machine parts, then assign to suitable machine center for machining. This study construct the shop floor control mechanism of aerospace machine shop which combine the concept of order release control, gateway control, queue level control, color code control, cycle time control, and apply the on-time dispatch and on-time completion as an indicator to monitor the performance of shop floor control. Thus, we can improve the weakness and increase the competitive advantages of machine shop in the global competitive aerospace market.