Factory Supply Research Articles

Embedded simulation on a multiprocessor job scheduling system with inspection

This paper first develops architecture for a multiprocessor job scheduling system with an embedded simulation technique. The architecture provides a shell for applications that are characterized by two scheduling policies, a heuristic algorithm policy and a First-In-First-Out (FIFO) policy. These policies are implemented in the simulation model by using the embedded technique. The paper evaluates these two policies using the queue length, waiting time and flow time as the criteria to compare the performance of these two scheduling policies. Next we designed two simulation situations using two different real world applications. The purpose is to examine the performances of multiprocessor systems with and without inspection operations and two different scheduling policies. The two applications, berth allocation for the container terminal operations and production scheduling arrangement in an Original Equipment Manufacturer (OEM) power supply factory, are studied. The final results show that a proper scheduling policy will perform better than the traditional FIFO approach for a multiprocessor system. Our study also provides guidelines on balancing a system with the addition of a final inspection activity.

Application of Cost Effective Solutions for Improving Voltage Sag Immunity of an Automated Cement Manufacturing Plant

Quality of the power supply becomes a key issue in factory automation. Especially voltage sags appearing on the electricity supply cause voltage sensitive equipment to shutdown and incurr heavy financial losses by interrupting the manufacturing process. However, effects of voltage sags can be minimized considerably if both the utility and the factory are working with good cooperation. This paper presents a Sri Lankan experience of finding out sag minimization or mitigation techniques through a study jointly carried out by the power supply utility and a customer. By analyzing the plant disturbance reordered for a five a year period and measurements taken with a sophisticated power quality disturbance recorder it has been observed that voltage sags appearing on the factory supply are mainly caused by faults and subsequent switching operations taking place on the transmission and distribution network of the power utility. In addition to that switching operations carried out in the factory owned distribution network also result in voltage sags. In this study, investigations were carried out for estimating the severity of voltage sags associated with different types of faults in the utility network and their effect on the equipment installed in the factory. Especially the effects of voltage sags on the equipment vulnerable for production process like large induction motors and vector controlled Variable Speed Drives (VSD) were investigated to find out the possibilities for improving their voltage sag immunity. Simulations are extensively used to describe field observations. Adequate theoretical descriptions are given to justify field observations and simulation results. Even though well proven sophisticated equipment is available for voltage sag mitigation these are not taken into consideration here due to their high cost. Instead, simple solutions such as distribution network rearrangement, reviewing protection settings and activating already embedded control algorithms in sensitive equipment are considered. Most of the solutions discussed here do not incur additional cost. Remarkablygood results have been gained by applying these techniques.

Challenges and Possibilities for Democratic Grassroots Union Elections in China

In 2001 and 2002, Reebok facilitated democratic trade union elections at two of its supplier factories in China. After initial successes in one factory in bargaining with management to improve conditions, in the end the experiment failed. This article describes in detail the election process, the elections’ aftermath, and the power dynamics of the actors involved (Reebok, the supplier companies’ management, the workers, their newly elected trade union committees, the district-level trade unions, and the Chinese trade union federation). The article analyzes the reasons behind this failed experiment and concludes by arguing that in a new changed climate today, both within China and within the international trade union movement, the Reebok experiment is worth reexamining.

From Passive Beneficiary to Active Stakeholder: Workers’ Participation in CSR Movement Against Labor Abuses

Corporate social responsibility (CSR) movement against labor abuses has gained momentum globally since the 1990s when many corporations adopted codes of conduct to regulate labor practices in their global supply chains. However, workers’ participation in the process is relatively weak until very recently, when new worker empowerment programs are increasingly initiated. Using conceptual tool created by stakeholder theorists, this article examines dynamics and performance of worker participation in implementation process of codes of conduct through a case study of CSR practices of Reebok at one of its footwear supplier factories in south China. Empirical data was collected during 2002–2005 through participant observation, in-depth interviews, and document reviews.

Design of a Factories’ Supply System with Biomass in Order to Be Used as an Alternative Fuel—A Case Study

Nowadays, the need for the use of alternative energy sources (except fossil fuels) as a fuel has shown a marked increase, especially in the sector of industrial production. This fact has been necessitated by the continuous rise of crude oil prices and by increased pressures to protect the environment, such as the Kyoto convention. Biomass of agricultural residues such as cotton stalks is considered as one of the alternative types of fuels. Cotton stalks were used as a fuel for household needs from the very early ages. The subject of this study is the determination of a company’s factory supply system with cotton stalk biomass in order to use it as a fuel. This study has taken place within the framework of the feasibility of such a supply system. It was proved that the substitution of conventional fuel in the industry sector by cotton stalk biomass is feasible technically and economically.

Too Weak for the Job

The shift of economic production from higher labour standard regimes in the global North to lower standard regimes in the South is undermining enforcement of global labour standards. Responding to criticisms from the ‘anti-sweatshop’ movement, consumers and governments, many transnational corporations (TNCs) have adopted codes of conduct to regulate labour standards in their supplier factories. Non-governmental organizations (NGOs) are increasingly used to monitor compliance with these codes. This article analyses the monitoring effectiveness of three kinds of such ‘third party’ NGOs. It concludes that major monitoring deficiencies reflect, first, significant organizational weaknesses of the NGOs and their dependence on TNCs for whom they monitor; second, powerful limits imposed on NGO effectiveness by corporate restructuring and market competitiveness; and third, inadequate pressures from anti-sweatshop movements, consumers and governments. These constraints suggest that this NGO-centred, ‘soft law’ policy approach is ‘too weak for the job’.

Q Fever Outbreak at a Cosmetics Supply Factory

Q fever is a zoonotic disease that is most commonly associated with outbreaks in slaughterhouses. We describe an outbreak of 4 cases occurring in a factory that processes ovine fetal products for the cosmetics industry. It is important that industries typically not associated with risk of Q fever are made aware of potential health risks that workers might be exposed to so further outbreaks might be prevented.

Silicosis in dental supply factory workers

Dental products contain a variety of potentially hazardous materials, including metals, organic chemical compounds, plastics, and inorganic mineral dusts. The risk of silicosis has been documented for workers of dental laboratories, but not dental supply factories, where the exposures could be expected to be higher. We report in this article five cases of silicosis, four of them with progressive massive fibrosis, in workers from two dental supply factories. This report underlines the need for effective occupational health programs in this type of industrial facilities.

Approaches to child labour in the supply chain

This paper examines the difficulties of dealing with child labour in the supply chain. It begins by identifying a number of the factors which make global supply chains so difficult to manage. It goes on to outline a framework of different approaches that can be taken to managing the supply chain with relation to child labour, moving from national and international regulation, through to the role of NGOs and the companies themselves. Focusing on an ‘engagement’ strategy for dealing with child labour, the paper traces a case study of Adidas‐Salomon and its attempts to implement their ‘standards of engagement’ in this area with relation to one of their supplier factories in Vietnam. The research draws on the direct involvement of one of the authors who visited the site and was able to interview staff and observe the operation in practice. Her findings are supported by wider work on the implementation of corporate approaches to human rights at a range of companies interviewed by another of the authors. The paper aims to highlight the issues needing to be addressed for companies considering the ‘involvement’ approach to child labour. It also aims to develop theory on our understanding of different approaches to corporate rights.

Asian Industrial Internet Strategies: Building Blocks for E-Commerce

The advent of the Industrial Internet technologies in Asia has altered the dynamics of the manufacturing sector requirements for competitive success. In examining many of the fundamental building block concepts deemed the ’required knowledge’ of e-commerce, be it production-related or market-related information (Glazer, 1999), the paper focuses on the development of an Industrial-focused strategic Internet initiative. In an industry where the consulting dollars may be as high as the software dollars, the key concept of an industrial Internet strategy is in viewing information as an enterprise-wide, multi-tier communications asset (Hoske, 1999). The Industrial Internet reaches not only from the front office to the factory floor, but from the factory floor to an authorized lap top anywhere in the world. Although there is an abundance of importance being placed in recent literature on sales force automation (SFA) and customer relationship management (CRM) software, advances in factory supply chain management software and systems offerings may prove to be of a more highly critical value. For reemerging Asian industrialists, too much importance cannot be placed upon their propensity for assimilating vital industrial Internet technologies, and transforming the vicissitudes of e-commerce markets toward the fulfillment of their own competitive advantage.

Trash, Heat, and Ash

This article highlights about process of incineration that offers French municipalities a number of advantages. First, it reduces the volume of solid waste to a fraction of its bulk. A metric ton of household waste leaves about 250 kg of bottom ashes and 30 to 50 kg of fly ash. This is an important consideration in France, which has much less landfill space than New World giants such as the United States or Canada. Combustion also sanitizes by destroying any microbes present, and the heat produced by the waste furnace can generate steam or hot water to heat residences, supply factories, or generate electricity in a turbine. Two popular French waste incinerator designs are rolling hearth and inclined grate furnaces. The former type contains a sloping series of rollers turned continuously by motor. As fuel slides down the rollers from top to bottom, solid residues drop out. Electricite de France is researching several ways of reducing the costs of vitrification. In laboratories near Fontainebleau, fly ash is fed into an electric arc furnace equipped with a graphite electrode.

The Struggles of Women Industrial Workers to Improve Work Conditions in the Progressive Era

Background Reading At the beginning of the Progressive Era, one in every five females over the age often was employed, and over a million . of these females worked in factories. By 1920, the number of working women increased to one in every four, with a significant number joining the ranks of industrial workers. These factory women were young and single, or women who had become widows, divorced, or abandoned. Seventy-five percent of them were foreign born or daughters of foreign-born parents (1). With their jobs varying as widely as their national origins, the only constant was their meager wages and poor working conditions. Paid less than men, women industrial workers were condemned to work long hours under sweatshop conditions, subjected to treatment that spoke of their inferior status in the workplace. In response to these hardships many industrial women acted collectively to challenge the conditions of their working lives. Women toiled in many industries, the breadth of their bread winning opportunities determined by their location and the availabil ity of resources. They worked among the sickly sweet smells ofthe candy factory. They rolled cigars, suffering nicotine poisoning when their hands became stained. In the artificial flower-making industry they created flowers for homes and hats while receiving one of the lowest wages of all, in 1905 less than $6 a week. Other women worked within the hot and humid climate ofthe laundries, starching men's collars and cuffs. The ethnic backgrounds of women industrial workers varied. In the Northeast, factories were filled with immigrants. In Lawrence, Massachusetts, for example, over forty languages were spoken in the mills. In the New York City garment industry, Russian Jewish women helped organize thousands of workers and spearheaded many strikes for better working conditions. Cuban women domi nated the Tampa cigar-making industry, while African-American women toiled in all seven laundries of Little Rock, Arkansas. Their distinctive experiences reflected their ethnic heritages and the particu lar nature of their factory jobs. Most factory experiences did not begin to offer the workers a sustaining wage. In 1905, an annual salary of $800 was considered the minimum necessary for survival for a family of four. The average factory salary, however, amounted to $400 a year (2). Since women earned from 25 to 67 percent less than men because of their sex, their incomes could hardly be considered a living wage. In addition, deductions for factory supplies such as needles or for seconds (those items determined imperfect by the foreman or manager) further reduced the pittances received. Over 40 percent of women industrial workers toiled in textile mills and the garment trade. Employer policies in this industry remained notorious throughout the Progressive Era. The practices of the Triangle Shirtwaist Factory epitomized the frightening lack of conscience of many factory and building owners. Joseph J. Asch, owner ofthe Asch building in which the Triangle Factory was located, insisted that his building was fireproof and complied with all fire regulations. Yet on 25 March 1911, 146 workers, most of them young women, died when fire flew through the locked work space at Triangle. Those who managed to find the one rusted fire escape tumbled to their deaths when it collapsed beneath their weight. In the trial that followed this tragedy, an all-male jury acquitted the Triangle owners. The cavalier attitude about the loss of life was summed up by one juror who said, I think that the girls, who undoubtedly have not as much intelligence as others might have in other walks of life, were inclined to fly into a panic (3).

Pasture response to fertiliser inputs under dairy grazing

Conversion of sheep and beef farms into dairy units has resulted in research on appropriate fertiliser rates and pasture species to achieve maximum productivity in minimum time. An onfarm trial involving five different mixtures of pasture species (based on fescue, prairie grass, an improved mixture, farmer mixture or original pasture), three rates of nitrogen as urea (0, 50 or 100 kg/ha of N applied half in March and half in August) and four rates of superphosphate (0, 250, 500 or 1000 kg/ha applied annually in March) was established in Canterbury on a Waimakariri sandy silt loam with border-dyke irrigation and an Olsen P of 5 pg/ml. The trial was grazed by dairy cattle as part of the general rotation; plots were not fenced individually. Pasture growth rates were measured pre- and post-grazing using a calibrated pasture probe. Botanical dissections ,were made seasonally and soil samples were taken annually. Pasture dry matter production was greatest from the prairie grass, "improved" mixture and the original pasture, involved often contain a high proportion of annual and perennial, low-producing species. Grass species, nutrient status and management have been identified as the limiting factors in dairy conversion (Kleyngeld & Kleyngeld 1992). Ryegrass and white clover are still the most common species used in pasture renovation (Maloney 1991). However, short-rotation ryegrasses are favoured by some dairy farmers, and in new dairying areas such as Canterbury, optimally producing species may differ from those used in the more traditional North Island dairying areas (Charlton & Belgrave 1992). Nitrogen (N) is recognised as a strategic tool for increasing grass production in winter-spring in summerdry areas (Thomsoneta/. 1991) as well as for extending the milking season for factory supply herds in Southland (Kleyngeld & Kleyngeld 1992). High rates of nitrogen (217 and 324 kg/ha per year) have been found to increase annual net herbage accumulation by 23 and 27%, respectively, in the Waikato, but clover content declined significantly (Harrisetaf. 1994). Maintenance fertiliser requirements have been related to desired stocking rate in the past, based on animal production system and soil type (Computerised Fertiliser Advisory System (CFAS), reaching 13 000,ll 000 and 16 000 kg/ha in years Cornforth & Sinclair 1984). Recently responses in milk one, two and three, respectively; production from yield have been recorded to very high rates (100 kg/ha- IT the fescue increased with time; the 'farmer' mix performed poorly. Nitrogen at 50 kg/ha was generally sufficient to produce maximum yield increases. Increasing superphosphate increased production; this effect decreased with time. Change in Olsen P reflected superphosphate inputs and after three years of differential superphosphate application the Olsen P status was 8, 14, 27 or 42 (corresponding to 0, 250, 500 or 1000 kg/ha superphosphate). Keywords: Bromus wildenowii, dairy conversion, dry matter production Festuca arundinacea, Loliumperenne, nitrogen, Olsen P, superphosphate

Production planning models for a central factory with multiple satellite factories

The production planning problem of minimizing total cost, which consists of transportation cost, processing cost, raw material holding cost, and finished product inventory holding cost in a network of factories involving a central factory and multiple satellite factories is investigated in this paper. Based on two different raw material purchase plans, two non-linear mathematical programming models are formulated. In the first model, the material ordering policy at any given factory is based on the aggregation of each raw material type demanded over all items to be manufacured in the factory during a given production period. In the second model, lot consolidation for ordering is not done. The raw materials for each item produced by a factory are ordered separately. These two models integrate the raw material supply factory selection problem, order size determination, order processing sequence, and material handling functions to define a cost-effective production plan. The results from the model define a p...

The role of computer-aided production management in CIM systems

Computer-integrated manufacturing (CIM) systems have been widely developed in western countries, and recognized as an effective production management model. The key problem is integration of hardware and software. More attention should be payed to software integration, especially to computer-aided production management (CAPM), without which it is unrealistic to make full use of all islands of automation and computer-aided management techniques in an enterprise. In this article emphasis is put on studying the relationship between CAPM and other components in a CIM system, and the role of CAPM in CIM systems. The conclusion is that the role of CAPM is the core of activities of an enterprise; the information pivot in a CIM system; the centre of planning and control to balance customer's demand with factory's supply; and the key subsystem for increasing productivity and shortening lead time.

Conversion of an eastern Southland sheep farm to factory supply dairy pasture: changes and implications for production

The Kleyngelds sharemilk a 135 hectare dairy farmm for Tasman Agricultme, converted from sheep in 1990. 350 cows are wintered with total production being 41 800 kg milkfat (90/W), 54 000 kg (91/92), and projected 92/93,57 000 kg. One third of the farm is in newer ryegrass/clover, the remaining mainly browntop. Grass grown and grazed is recorded, so paddock performance can be monitored. The major result is variation in growth, 1 l- 3 tonnes/DM. A grazing round of approximately 26 days suits all pastures for best performance. A balance is created between under- andovergrazing. Pasture is grazed to a base level of 1400 kg/ha/DM, to ensure quick regrowth but no loss of quality. Regrassing is the major emphasis -- approximately lo-20 hectares are done a season. Ryegrasses and clover are used at 23 kg/ha. Pasture is sprayed and direct drilled with care taken in grazing for first season. Fertiliser complements regrassing. Over the last two years 400 kg/ha 15% potassic super was applied, this season 600 kg/ha were applied. Nitrogen is used strategically from.late winter to autumn according to soil temperature over the whole farm. There are flow on effects through winter and early spring. Limiting factors to conversion are management, fertility and grasses. Planning is needed to utilise resources for best returns. Keywords dairy conversion, fertiliser, regrassing, sheep farm, dairy farm

Phosphorus supplementation of lactating dairy cattle on a Northland farm

Forty-eight Friesian or Friesian-X factory supply dairy cows were divided into two groups. Group 1 received a supplement of sodiumtripolyphosphate (TPP, 25g P, 25g Na/cow/day), and group 2 a supplement of sodium chloride (25g Na/cow/day). Supplementation began at peak lactation, when the mean serum inorganic phosphorus (Pi) of all cows was 1.13 mmol/l. After four weeks, group 2 changed from NaCl to dicalcium phosphate supplementation (25g P/cow/day). Serum Pi and yields of milk, butterfat and protein were measured before, during and after supplementation. Pasture availability was assessed and P and Ca contents in pasture and the Pi content in milk were also determined. Supplementation raised serum Pi from 1.30 mmol/l (NaCI) to 1.42 mmol/l (TPP, P<0.05) but when dicalcium phosphate replaced NaCl the difference between groups disappeared (P>0.05). P supplementation had no effect on any milk parameter. Pre-grazing pasture mass above estimated grazing height averaged 2260 kg DM and contained >or=0.39 per cent P. It is concluded that a herd mean serum Pi concentration of around 1.2-1.3 mmol/l imposes no limitation to dairy production around the period of peak lactation of grazing dairy cattle.

A survey of the phosphorus and calcium contents of pastures and the serum inorganic phosphorus and calcium contents of cows on four Manawatu dairy farms

Serum inorganic phosphorus (Pi) and calcium (Ca) concentrations were assessed in 20 cows on each of four Manawatu factory supply dairy farms. Blood was taken from each cow before calving and at six-week intervals during lactation. Bleeding coincided with herd testing. Herds of Friesian or Friesian X cows and Jersey or Jersey X cows were compared on adjacent farms on a Central Yellow-brown Sand and on adjacent farms on a Peat Loam overlying a Central Yellow-brown Earth soil. Pasture mass and composition were estimated to grazing height in the next two paddocks to be grazed in the rotation. Mean serum Pi concentration was higher in cows on sandy soils (1.55 mmol Pi/l than in cows on the peat loam (1.34 mmol Pi/l (P<0.001). Concentrations were highest before calving (1.69 mmol Pi/l) but fell to low levels at peak lactation (1.17mmol Pi/l when 70% of cows were below the minima of the 'normal range', and during the drought (1.29 mmol Pi/l. Pasture phosphorus (P) concentrations were adequate to support cow nutrition for lactation (>0.33% DM, ad lib. feeding) until the summer drought when low herbage mass would have restricted milk production. Serum Ca was adequate for lactating cows and changed little between months or between cows (mean 2.12 mmol Ca/l). No metabolic disorders relating to mineral deficiencies were observed. It appears that serum Pi in a high proportion of cows falls below the normal range during peak lactation without cows displaying clinical deficiency symptoms or a depression in butterfat production.

Selenium response in dairy cattle

Abstract Extract Madam:- We wish to report the findings of selenium (Se) response trials in three Taranaki factory supply dairy herds.

A survey of the phosphorus content of pastures and the serum inorganic phosphorus content of dairy cows

Serum inorganic phosphorus (Pi) concentration of 20 cows in each of ten factory supply dairy herds was assessed at monthly or two-monthly intervals during the 198243 lactation. Pasture on offer was ranked low, medium or high and the phosphorus (P) content assessed monthly on all farms from the two paddocks to be grazed next in the rotation. The mean serum Pi concentration was high (1.98 mmol/l) prior to calving but fell to low levels at peak lactation (1.28 mmol/l) and again during the drought (1.28-1.38 mmol/l) in January, February and March. Individual cows had Pi levels as low as 0.32 mmol/l. Herds on Northern Yellow-brown Earths had higher Pi levels than herds predominantly on Brown Granular Loams (P<0.01). There were differences between cows within herds (P<0.01) and Pi levels declined with cow age (P<0.01). Pasture P content was above minimum requirements for lactating cows (0.33% DM; with ad lib. feeding) from July through October but below requirements in most pastures from December through April, when pasture availability also limited production. The P content in pasture was unrelated to either its grass or legume content, but was higher in pastures given a medium or high DM ranking (P<0.05). The possibility of increasing dairy production with P supplementation in spring is discussed.