Lower Lead Time Research Articles

Supporting framework to improve Engineer-To-Order product lead-times

Company's competitive advantage can be achieved through its agile capability to satisfy customers’ needs by developing and manufacturing efficiently customized products. So performing ETO (Engineer-To-Order) product with lower lead-times is a real challenge that requires new approaches. This paper investigates a new framework to help decision-makers in adopting the right management systems to organize customer order fulfillment from request to delivery. The European Project “ESTIMATE”, Eurostars Program, is lead to sustain successful ETO processes. The ESTIMATE framework aims at providing guidelines to perform successful ETO product. Main drivers for ETO product fulfillment are identified regarding several dimensions and a strategy of decreasing lead-times is explored and discussed in detail. This strategy is called “shifting strategy“.

Using value engineering to optimize flood forecasting and flood warning systems: Golestan and Golabdare watersheds in Iran as case studies

Flood occurrence has always been one of the most important natural phenomena, which is often associated with disaster. Consequently, flood forecasting (FF) and flood warning (FW) systems, as the most efficient non-structural measures in reducing flood loss and damage, are of prime importance. These systems are low cost and the time required for their implementation is relatively short. It is emphasized that for designing the components of these systems for various rivers, climatic conditions and geographical settings different methods are required. One of the major difficulties during implementing these systems in different projects is the fact that sometimes the main functions of these systems are ignored. Based on a systematic and practical approach and considering the components of these systems, it would be possible to extract the most essential key functions of the system and save time, effort and money by this way. For instance, in a small watershed with low concentration and small lead time, the main emphasis should be on predicting and monitoring weather conditions. In this article, different components of flood forecasting and flood warning systems have been introduced. Then analysis of the FF and FW system functions has been undertaken based on the value engineering (VE) technique. Utilizing a functional view based on function analysis system technique (FAST), the total trend of FF and FW functions has been identified. The systematic trend and holistic view of this technique have been used in optimizing FF and FW systems of the Golestan province and Golabdare watersheds in Iran as the case studies.

Establishing rules to design a minicell-based manufacturing system for mass customisation

Mass Customisation (MC) is the production of individually customised offerings at low cost and short lead times. Successful MC requires a complete shift in the paradigm from the design-make-sell philosophy used in traditional manufacturing to one that is based on design-sell-make. Flexibility in the manufacturing system is therefore essential to receive orders from customers and fabricate and assemble products as necessary. A minicell-based manufacturing system, which is a modular, networked configuration, is one approach to achieve this flexibility. Due to the various methods available to design the modular minicell configuration, establishing good designs is a complex and time-consuming process. This paper focuses on establishing design rules that can help identify good minicell configurations, to achieve different performance criteria, without having to explore the entire solution space.

The Linkage between Logistics Activities and Firms' Performance: An Empirical Study

The main objective of this paper is to analyse the impact of a set of logistics activities on firm's performance. To reach this, a performance measurement system is proposed. The logistics activities studied are the ones related with warehousing, that is, inventory control, handling, packaging, picking and also the warehousing activity. Structural Equation Modelling (SEM), in its non-parametric approach (Partial Least Squares - PLS), was performed in order to test the hypotheses formulated and the reliability of the structural model proposed. The empirical results of this study indicate that the practices developed within the logistics activities have an influence on firms' performance, mainly in their costs. Moreover, the activity that seems to have a high impact on firms' performance is the inventory control. In this sense, a special attention must be given to the way logistics activities are performed whether firms want to have not only higher responsiveness to market and higher quality of their products and services, but also lower lead times, and costs.

A modular minicell configuration for mass customisation manufacturing

Mass customisation aims at providing products and services to meet individual customer needs at near mass production efficiency. Successful mass customisation requires a manufacturing system that is highly flexible to adapt to customer needs, has low lead times, and enables customisation at a low cost. Developing a manufacturing system to achieve all these requirements, which seemingly is a paradox, is one of the major challenges to successful mass customisation. This paper presents an approach to configure the manufacturing system as a collection of minicells, dedicated to producing option families, to which products can be routed depending on the customisation needs of each customer.

Managing Inventory and Supply Performance in Assembly Systems with Random Supply Capacity and Demand

We consider stock positioning in a pure assembly system controlled using installation base-stock policies. When component suppliers have random capacity and end-product demand is uncertain, we characterize the system's inventory dynamics. We show that components and the end product play convex complementary roles in providing customer service. We propose a decomposition approach that uses an internal service level to independently determine near-optimal stock levels for each component. Compared with the optimal, the average error of the decomposition approach is 0.66% across the tested instances. Compared with current practice, this approach has the potential to reduce the safety-stock cost by as much as 30%. Our computational analysis on two-echelon systems also illustrates several managerial insights: We observe that the cost reduction from improving supply performance is high when demand variability or the number of components or target customer service is high, or when the end product is more expensive relative to components. On average, (i) reducing the lead time of the more expensive component yielded higher benefit than reducing the lead time for the less expensive component, and (ii) the benefit of improving one of the supply parameters (service level or lead time) was higher when the value of the other parameter was already more favorable (lower lead time or higher service level, respectively). Finally, we analytically show how a multi-echelon pure assembly system may be converted into an equivalent two-echelon assembly system to which all our results apply.

Update on screening and early detection of prostate cancer.

The aim of this review is to discuss advances in the field of screening and early detection of prostate cancer from papers published in 2003. The fall in distant prostate cancer mortality accounted for the overall decline in cause-specific mortality rates in the USA. In the European prostate cancer screening trial (European Randomized Study of Screening for Prostate Cancer), there is considerable stage migration towards organ-confined disease, which becomes more pronounced in the second screening round. The high sensitivity of the screening protocol (approximately 90%), low interval cancer rate (13-19%) and lead time estimates of 10 years and longer support a 4-year screening interval, current procedure in the European Randomized Study of Screening for Prostate Cancer trial. Advances achieved in research on the discriminative power of the free prostate-specific antigen forms, particularly pro-prostate-specific antigen, have progressed and may be introduced in cancer detection at low prostate-specific antigen levels rather than a further reduction of the current prostate-specific antigen threshold. Definitive evidence on the effectiveness of prostate cancer screening with prostate-specific antigen should come from the ongoing European Randomized Study of Screening for Prostate Cancer and Prostate, Lung, Colorectal and Ovary cancer trials, and should further elucidate the debate about the appropriate prostate-specific antigen threshold. Free prostate-specific antigen sub-forms offer prospects for prostate cancer detection at low prostate-specific antigen levels.

Enterprise systems development model

Organisations strive to increase profits through better market share and lower operating costs whilst maintaining other performance goals such as high quality and low lead-times. This often requires a company to conduct its operations differently to the way it currently operates. A company must be willing to change and a key factor in achieving its desired goals is effectively managing that change. The development and execution of a comprehensive change management program is crucial for achieving business goals and the integration of many change initiatives characterises successful change management. In order to achieve this integration, many aspects of an organisation, many concerns regarding performance measures, and many types of change requirements must be considered holistically. These considerations imply a complex research domain. This paper presents a study of methods and supporting tools for facilitating the development of an effective change management plan in industrial enterprises. The study is based on a set of theoretical models about how change occurs in organisations and organises key principles into an integrated model. The model is called enterprise systems development (ESD). ESD facilitates the process of deploying change within an organisation by identifying the parameters around three core business elements – the change process, performance measurement, and enterprise objects. It presents a systematic performance-based approach to business transformation and offers an innovative and adaptive change management style. ESD collects many change activities currently presented under different banners into one single management schema. It has been validated in a number of large enterprises during the development phase of their change programs. It has proven to be a critical first step in helping managers understand where they are now and where they need to change in the future.

A multi-phase mathematical programming approach for effective supply chain design

A supply chain is an alliance of independent business processes, such as supplier, manufacturing, and distribution processes that perform the critical functions in the order fulfillment process. Effective design and management of supply chains assists in production and delivery of a variety of products at low cost, high quality, and short lead times. Although the importance of supply chain design is emphasized in the literature, few formal decision models have been proposed for this purpose. This paper presents a multi-phase mathematical programming approach for effective supply chain design. More specifically, the methodology develops and applies a combination of multi-criteria efficiency models, based on game theory concepts, and linear and integer programming methods. Model application and insights are detailed through numerical illustrations.

Improving manufacturing costs and lead times with quality-oriented operating curves

The attainment of products conforming to demanded specifications requires appropriate manufacturing processes. The most widely adopted measure of process adequacy to hold the tolerances is the process capability. This characteristic value describes the relationship between measured variations of a product’s features turned out by the process and its assigned tolerances. The process capability has a great effect on the portion of rework and scrap. The network structure of a job shop production leads to complex interactions between the individual manufacturing processes and inspections. Therefore, the effects of process capability on the quality of products on one hand, and especially on manufacturing costs and lead times on the other hand are difficult to evaluate. Since an analytical approach is not possible, simulation is used to model manufacturing processes and inspections and to investigate the effects. To visualize the complex interactions between quality, manufacturing costs, and lead times quality-oriented operating curves have been developed and are presented in this paper. By means of these operating curves the production planning engineer can choose from among competing processes that one, which is most appropriate for meeting the global economic objectives of high quality, low manufacturing costs as well as low lead times.

Introducing JIT Manufacturing: It's easier than you think

T he practical difficulties arising from the implementation of a Just-in-Time (liT) inventory management approach have caused some managers to dismiss it as a passing fad. When asked to cite the inventory strategies that do and do not work for their companies, purchasing managers identified JIT as the most frequently mentioned failure. Their general sense was that modified JIT works, pure JIT does not. The success of JIT implementation may also be a function of the size of the company, with smaller firms finding it more difficult. If JIT is abandoned because it does not appear to work as described in articles and textbooks, the cost savings of an efficient, integrated manufacturing process will be lost. As documented here, the solutions of actual companies in response to the impediments of introducing JIT in its purest form may be instructive for other firms facing similar problems. The popularity of JIT inventory methods has grown steadily over the last two decades. Officially introduced by Toyota in the 1970s, JIT methods have spread to manufacturing companies all over the world. The appeal lies mostly in an emphasis on simplicity and a cost-saving, bare-bones approach. Researchers generally agree about JIT on several points, one being that JIT methods, with some alteration, can be successfully adapted for use in American manufacturing plants of all sizes. Setting up a JIT system, however, inw)lves the entire business, from suppliers to production to customers---even to administrative aspects such as accounting. There may be significant disadvantages with the system, such as uncooperative suppliers, the distance between suppliers and manufacturers, and overstressed workers. On the other hand, the benefits to be realized include less need for maintaining safety stock, a lower lead time, higher quality, automated communication with customers, and cross-training for workers. A JIT approach has as its main goal the reduction of the levels of inventory and its associated carrying costs--or to reduce waste altogether. The less time a product is in process, the less inventory there is to finance, store, and manage. The objective is to push to zero the amount of time the product is waiting to be worked on, in transit, and/or being inspected. Benefits that should result from the implementation of a JIT system include: • lower inventory carrying costs; • space and cost savings in the factory and warehouse; • reduced risk of obsolescence; and • reduced response time to customers' orders and delivery times. To the extent that the JIT system can be put into practice without any impediments, a theoretically correct demand-pull system will be in place. JIT in theory often differs greatly from JIT in practice. Not all companies can continuously feed inventory into work-in-process and manufacture their product without interruption. Different industries have different manufacturing processes that, for varying reasons, are not suited to JIT treatment. This does not completely rule out the possibility for the company to practice JIT; it just means it has to find a way to adapt or adjust its processes to incorporate as many JIT principles as possible. To examine how different manufacturers have adapted JIT to fit the needs of their compa-

A new method for order release

A new method for determining when to release jobs into a probabilistic manufacturing line is described. This new heuristic releases jobs only if their predicted waiting times are sufficiently estimated using simulation. Moreover, we use simulation to examine the performance of this heuristic and others CONWIP, Starvation Avoidance for a manufacturing flow line with exponential machine processing, failure, and repair times. The reasons why it is appropriate to compare order release mechanisms using tradeoff curves of lead time versus customer service are described. The simulation experiments show that the new 'waiting time heuristic' is superior to other order release mechanisms in situations where low lead time is required. small. Waiting times are

Period batch control in group technology

Abstract Group technology (GT) offers many advantages to firms engaged in batch manufacturing, including lower setup times, reduced lot sizes, lower lead times, and easier production planning and control. Period Batch Control (PBC) has been proposed in the literature as a simple production planning and control system for a GT environment, based on the choice of a cycle length. Unfortunately, there are no published studies providing guidelines for the choice of an optimal cycle length. In this paper we develop a cost minimization model for examining the choice of cycle length, and demonstrate its use by applying it to four published data sets. The analysis shows that the cell design itself directly affects total inventory and overtime costs and the choice of cycle length; that demand increases can be very expensive for a given cell design; and that the degree of demand uncertainty is an important factor in PBC design. The key managerial consideration is the amount of slack capacity to build into the cell d...

Job shop leadtime requirements under conditions of controlled delivery performance

A model that facilitates setting due dates on the basis of forecasted flowtimes and estimated forecast error has recently been developed. This model, called the Dynamic Forecasting Model, allows job shop delivery performance to be controlled. Quoted leadtimes can therefore be used as a measure of shop floor control performance. This paper investigates the leadtime performance under various types of dispatch. Results show that when the percentage of tardy jobs desired is low and the utilization level is high, due-date dependent dispatch facilitates using lower leadtimes than due-date independent dispatch. Within the due-date dependent group of dispatch rules tested, leadtime behaviour is very similar. Furthermore, performances using operation and job due dates are quite similar. When due dates are set in a manner allowing delivery performance to be controlled, evidence suggests that differences in leadtime requirements are less affected by the dispatch rule choice than by the utilization level and the desired level of delivery performance.

Frame relaying as a common access to N-ISDN and B-ISDN data services

Widespread use of personal computers (PCs) and PC networks is leading to a strongly increased demand for WAN data services in terms of number of accesses and required bandwidth. Narrowband ISDN (N-ISDN) and broadband ISDN (B-ISDN) have the potential to satisfy, respectively, the existing and developing requirements. However, a flexible evolution path needs to be identified for the provision of ISDN access facilities. Frame relaying and frame switching are prime candidates for such a common access facility, although not necessarily intrinsic B-ISDN data services. The article gives an overview of frame relaying and frame switching as possible candidates for harmonized access to N-ISDN and B-ISDN. Pre-ISDN, N-ISDN, and B-ISDN services with their characteristics in terms of cost and performance are first described. It is shown how frame relaying and switching are positioned with respect to the identified service requirements. Then some examples are given of selected scenarios, and the role played by specifically frame relaying to provide access to B-ISDN services, offering at the same time a seamless evolutionary path from N-ISDN to B-ISDN. The position of frame relaying and switching is discussed first in respect to application requirements, and then in architectural terms. Frame relay (and frame switching) services are then identified as services that provide the necessary low threshold and short lead time for rapid market penetration, in order to allow applications to indirectly take advantage of the benefits of ATM services. >

Modelling of Indian monsoon rainfall series by univariate box—Jenkins type of models

The time domain approach, i.e. Autoregressive (AR) processes, of time series analysis is applied to the monsoon rainfall series of India and its two major regions, viz. North-West India and Central India. Since the original time series shows no modelable structure due to the presence of high interannual variability, a 3-point running filter is applied before exploring and fitting appropriate stochastic models. Out of several parsimonious models fitted, AR(3) is found to be most suitable. The usefulness of this fitted model is validted on an independent datum of 18 years and some skill has been noted. These models therefore can be used for low skill higher lead time forecasts of monsoon. Further the forecasts produced through such models can be combined with other forecasts to increase the skill of monsoon forecasts.

Electricity in the global energy scene

Owing to the many advantages and versatility of electricity, its share in the global demand for energy in final use is increasing. In 1990, global electricity generation amounted to 11 700 TWH and fuels for electricity production consumed 36% of the total global primary energy needs; which is more than twice their share in the 1950s. More than half of the electricity consumption occurs in OECD countries, however prospects for future demand growth are in developing countries. With increasing populations, higher economic growth, and the present modest use of electricity and energy, these countries are likely to consume a larger share of the electricity market in the future. Their demand growth rate will most likely be moderated by an acute shortage of capital. Future electricity generation technologies will aim towards improving efficiency, clean emissions, low capital cost and short lead times. Therefore, gas turbines and combined cycle plants will gradually assume a larger share of the power generating equipment market. For many decades to come, coal, because of its abundance and cheapness, will remain the world's major fuel for electricity generation. Natural gas, owing to its cleanliness, will be more in demand. However, the shares of hydro- and nuclear fuel, owing to their highly capital intensive nature and other considerations, are not likely to increase.

A systems approach to the implementation of JIT methodologies in Lucas Industries

Competitive modern manufacturing businesses must operate total materials flow control systems to ensure low stock levels and short lead times. When a variety of products is produced, to achieve just-in-time operation relevant to the overall business time-constants, composite control systems are needed within the factory, supported by matching supply processes and levelled output scheduling.