Changeover Cost in Garment Production

With the increase of style variation, decrease of lot size and shortening of lead-time, production planning becomes a big problem in clothing industry. It was found that changeover cost is one of key factors in garment production. In this paper, based on time measurement and the data collected, considering the relevent elements such as previous experience, lot size, number of lines,the effect of changeover cost on garment production is calculated and analyzed. Then some suggestions are put forward for manufacturers to balance their production planning.

Dynamic Performance Prediction in Batch-Based Assembly System with Bernoulli Machines and Changeovers

Worldwide competition and diverse demand of customers pose great challenges to manufacturing enterprises. How to organize production to achieve high productivity and low cost becomes their primary task. In the mean time, the rapid pace of technology innovation has contributed to the development of new types of flexible automation. Hence, increasing manufacturing enterprises convert to multi-product and small-batch production, a manufacturing strategy that brings increased output, reduced costs, and quick response to the market. A distinctive feature of small-batch production is that the system operates mainly in the transient states. Transient states may have a significant impact on manufacturing systems. It is therefore necessary to estimate the dynamic performance of systems. As the assembly system is a typical class of production systems, in this paper, we focus on the problem of dynamic performance prediction of the assembly systems that produce small batches of different types of products. And the system is assumed to be characterized with Bernoulli reliability machines, finite buffers, and changeovers. A mathematical model based on Markovian analysis is first derived and then, the analytical formulas for performance evaluation of three-machine assembly systems are given. Moreover, a novel approach based on decomposition and aggregation is proposed to predict dynamic performance of large-scale assembly systems that consist of multiple component lines and additional processing machines located downstream of the assemble machine. The proposed approach is validated to be highly accurate and computationally efficient when compared to Monte Carlo simulation.

Insights of numerical simulations of magnetohydrodynamic squeezing nanofluid flow through a channel with permeable walls

An analysis related to the transport of nanofluid that is confined in a channel between two orthogonal permeable walls will be investigated with the help of two numerical techniques.With the aid of the reasonable similarity changeover;the said model will be shaped into the desired non-linear equation whose behavior will be explained analytically as well as graphically where the functioning of three disparate variables such as magnetic parameter,permeable Reynold number,and channel permeable ratio will be explained precisely.The said model has been controlled by the homotopy analysis method(HAM)and then,compared through an efficient numerical method named shooting method(ShM).The profiles show that increases in the magnetic parameter decline the nanofluid flow velocity,whereas magnitude-wise raise is shown in each axial velocity profile.The radial profile raises while getting variation in wall expansion parameter from negative to positive.For the entire domain,the rate of change in velocity description enhances at the center while reduces at the surfaces.And the outcomes disclose that the wall permeable ratio has a significant impact on the solutions.Since the zero value of wall ratio refers to the particular type that Terrill has discussed.

The Upheaval in West Asia and North Africa:A Constructed New Viewpoint of World Security

The Arab political transformations originally occurring in early 2011 are posing negative impact over China’s overseas interests in the Middle East region,including those related to its trade with the Arab world,the China-Middle East bilateral investments,its contracted projects,and the safety of its nationals living in the Middle East,whether these influences are direct or indirect,overt or covert.Three aspects are strongly impacted by these negative influences:1)Libya;2)Northern and southern Sudan;3)Energy supply.The dramatic changes of the Arab world have brought alerting signals to China over its national interests in the Middle East,so China shall undertake a meticulous review of its overseas activities and draw the correct lessons from its experiences there so that practical responses can be worked out.In consideration of the loss that Chinese corporations have suffered from the Arab political changeovers,China should establish its own grand strategy for its foreign relations so as to protect its growing overseas interests.