Schedule Nervousness Research Articles

Production rescheduling via explorative reinforcement learning while considering nervousness

Nervousness-aware rescheduling is essential in maximizing the profitability and stability of processes in manufacturing industries. It involves re-optimization to meet scheduling goals while minimizing deviations from the base schedule. However, conventional mathematical optimization becomes impractical due to high computational costs and the inability to handle real-time rescheduling. Here, we propose an online rescheduling agent trained by explorative reinforcement learning that autonomously optimizes schedules while considering schedule nervousness. In a static scheduling environment, our model consistently achieves over 90% of the cost objective with scalability and flexibility. A computational time comparison proves that the reinforcement learning methodology makes near-optimal decisions rapidly, irrespective of the complexity of the scheduling problem. Furthermore, we present several realistic rescheduling scenarios that demonstrate the capability of our methodology. Our study illustrates the significant potential of reinforcement learning methodology in expediting digital transformation and process automation within real-world manufacturing systems.

Production Schedule Nervousness as a Strategic Business Trade-Off in North American Automotive Oems

Production Schedule Nervousness as a Strategic Business Trade-Off in North American Automotive Oems

Optimization Model Schedule Nervousness in Flight Catering Industry

Abstract―Instability often occurs in production planning, which is also known as schedule nervousness. This phenomenon triggers companies to make various efforts in minimizing the level of instability. In this study, the author tries to look at the schedule nervousness problems of the aviation catering industry in determining the amount of production planning to increase profits. In the context of schedule nervousness, there is a very high difference between the value of the temporary demand which is known 10 hours before with the fix order when the airline has closed the check-in process. This phenomenon makes the aviation catering company must bear the loss in value of the difference in demand that occurs. In one month the company must bear the loss of at least 500 packs of food. Based on those problems, the author tries to make an optimization model with linear programming by determining the number of orders for each airline and class of passengers at a certain service level to produce minimal inventory with large profits. The completion of the model using Lingo software is running well and has produced an optimal solution. The potential cost reduction carried out in the first week of January 2020, has provided the best scenario with the potential for cost savings of the production process around the production cost of around Rp 53 million or about 23%.

Effectiveness of nervousness reduction policies when capacity is constrained

A number of studies have examined a variety of solutions for overcoming master production schedule nervousness which is a major cause of cost increase and material flow disruption throughout the supply chain. The study reported in this paper provides a comprehensive review of the literature and provides insights on the effect of capacity constraints on the effectiveness of policies for dampening schedule nervousness. The insights on the impact of capacity constraints are then confirmed via a simulation study investigating the effectiveness of three nervousness reduction policies. The relative effectiveness of the policies (freezing a portion of the schedule, using safety stock at the end item level, and a combination policy of freezing and safety stock) are examined under a variety of conditions characterised by variations in the level of demand uncertainty faced by the system and product structure complexity.

Analysis of production planning in a global manufacturing company with process mining

PurposeThe purpose of this paper is to present the result of using process mining to model the production planning (PP) process of a manufacturing company that is supported by enterprise resource planning (ERP) systems.Design/methodology/approachThis paper uses event logs obtained from the case company’s ERP database. The steps for this research are planning process mining implementation, extraction and construction of event log, discovering process model with Heuristic Miner and analysis.FindingsProcess model obtained from process mining shows how the PP is actually conducted. It shows the loop in materials requirement planning and create plan order process. Furthermore, the occurrences of changing plan order date and production line indicate the schedule instability in the case company. Further analysis of the material management (MM) event log shows the implication of production plan changes on MM. Continuous change in the plan affects material allocation priority and may result in a mismatch between production needs and the materials available.Research limitations/implicationsThe study is only conducted in a single and specific case. Therefore, even though the findings provide good insight, the use of solitary case study does not imply a general result applied to other cases. Hence, there is a need to conduct similar studies on various cases so that a more generic conclusion can be drawn.Practical implicationsThe result provides insights into how the current company’s policy of adjusting the production plan to accommodate changing demand impacts their operation. It can help the company to consider a better balance between flexibility and efficiency to improve their process.Originality/valueThe paper demonstrates the use of process mining to capture the real progression of PP based on the data stored in the company’s ERP database, which give an insight into how a real company conducts their PP process, the implication of schedule instability on MM and production. The novelty of this research lies in the use of process mining to attest to the schedule nervousness issue at a process level.

How schedule issues affect drug logistics operations: an empirical study in hospitals in China

Purpose – The drug logistics play a crucial role in the hospital service performance. It has been proved that modern logistics concept is a valid access to competitiveness. In order to enhance the comprehensive capability and core competence of hospitals, including the internal support system, there is a great need to have an in-depth and systematic study on the drug logistics system in hospitals. The purpose of this paper is to explore the current situation of the drug logistics and the drug centres operations in public hospitals in China; specifically how the organizational partnerships with the supply chain partners can affect the operational performance. Design/methodology/approach – In this study, the possibility of correlations between schedule instability, partnerships with supply chain partners, and internal drug logistics operation is investigated by modelling, with reference to the previous work of Law et al. (2009), in which collective efficacy of the performance is incorporated into the model. Findings – The findings of this study show that the drug logistics working teams in public hospitals in China have a high level of efficacy and self-confidence, while they perceive they provide good operations even at a low level of schedule nervousness. The study also reinforces the significant correlation between internal operation and partnership with customers. This is definitely useful for the development of an appropriate framework for drug logistics operation improvement in the long run. Originality/value – The study thus offers a good reference for the administrators and practitioners who are keen on improving the service operations in the healthcare sector in the region.

Advanced Supply Chain Information for Rule-Based Sequence Adaptions on a Mixed-Model Assembly Line with Unreliable Just-In-Sequence Deliveries

The proliferation of just-in-sequence (JIS) deliveries has raised the vulnerability of assemblies to costly production stoppages or rework due to missing components. Through a comprehensive real-time supply chain monitoring systems, these supply issues can be detected early and affected orders removed from planned assembly sequences in time to avoid production disturbances. Using simulation analysis, this paper explores the impact of unreliable JIS deliveries and the mitigation potential of transparent supply chains that allow a rule-based order resequencing on a mixed-model assembly line. The results indicate that (i) rework due to unreliable JIS deliveries can be eliminated and (ii) the trade-off between schedule nervousness and optimality can be balanced, making the proposed rule a feasible approach.

Airline catering service operation, schedule nervousness and collective efficacy on performance: Hong Kong evidence

Carriers the world over depend on airline catering service providers to manage the catering and logistics of these complex operations. The logistics of onboard catering service material between suppliers, warehouses and the caterers differ significantly from the classical material flow in other industries between the suppliers, manufacturers and customers. The airline catering business can tolerate minimal flexibility relating to scheduling issues. Continuous changes in the schedule can undermine the confidence in the system and result in disruptions in the production or delivery systems. This study aims to study how the various determinants are correlated with schedule instability of the airline catering operations. The findings show the significant correlation between internal operation and relationship with customer, which affect the work efficacy at the collective level.

Sustaining effective business value chain: future challenges

PurposeThe purpose of this paper is to describe key factors in sustaining effective business value chains for companies operating in the electronic industry and identify their potential future challenges.Design/methodology/approachThe research methodology includes the survey development, the hypothesis development, and the statistical analyses, especially the Pearson correlation. Altogether, a total of 129 firms participated in this study – 97 companies from Hong Kong/China and 32 firms from Thailand. Included in this methodology are a pre‐test of a survey, a development of the research hypotheses, and follow‐up discussions with participating executives on possible future challenges for their business value chains.FindingsAn effective business value chain essentially depends on a good internal operational system and constructive relationships with suppliers and customers. In other words, the collective efficacy depends on a manufacturer's internal operations (IO) and its supplier and customer partnership. Owing to the extensive information and communication technology (ICT) applications, the concern relating to schedule nervousness has been greatly reduced.Practical implicationsThe key future challenges for an electronic manufacturer's business value chains are ICT standardization (i.e. data harmonization) for better sharing and transfer with both customers and suppliers and within a manufacturer's IO, and risk management.Originality/valueThe findings underline the importance of data harmonization and an adaptation of ICT standards such as control objectives for information and related technology and projects in controlled environment for managing design and deployment of ICT projects and their related risks.

A comparative study of schedule nervousness among high-tech manufacturers across the Straits

High-tech firms are facing multiple challenges in a competitive market. Among the multiple challenges, scheduling nervousness has been a critical issue concerning the high-tech manufacturers. The purpose of this study is to investigate the relationships between the various schedule nervousness determinants (relationships with business partners, internal operation) and to study the impacts of schedule nervousness on the individuals dealing with scheduling issues in the supply chain (i.e., collective efficacy), among the high-tech manufacturing firms in the region (Hong Kong and Taiwan). A research framework linking schedule instability and contributors (suppliers/customers and internal operation) and individuals (perceived efficacy) is applied. The study sheds light on the relationships between scheduling instability and various determinants in the supply chain.

Studi Eksperimen Faktor-Faktor yang Berpengaruh Terhadap Schedule Nervousness

Schedule Nervousness is defined as the number of time and amount changes in planning of order releases. It is one of the factors affecting execution effectiveness on MRP system. The purpose of this research is to evaluate factors predicted affecting nervousness on MRP system by using simulation method. The main factors considered include forecasting accuracy, orgering, and leadtime uncertainty. This research will also evaluate the effect of selection of lot-sizing decision and cost structure ob MRP system nervousness by using experimental simulation. The result shows that the most affecting factor on schedule nervous-ness is cost structure. According to the result, it concludes that the most effective technique for reducing nervousness, firstly, is to lessen natural order cycle by shortening set up duration and using just-in-time elements. Secondly, is to select lor-sizing method properly.

Schedule nervousness in a manufacturing system: a case study

Schedule nervousness has received significant attention from the academics for almost three decades. However, the majority of published works on schedule nervousness have relied upon experimental results as a basis for making conclusions and there appears to be very little field-based evidence presented in the relevant literature. This paper presents a case study of schedule nervousness based on field observations in a shoe manufacturing company in Indonesia. A model to quantify nervousness is also presented. This study provides an insight that schedule nervousness is an important issue in practice and efforts to quantify nervousness, as well as to understand how it occurred, are necessary in order to reduce nervousness.

Measurement of instability in multi-level MRP systems

Many researchers have addressed the issue of nervousness in schedules. Experimental studies dealing with this issue have focused mainly on single-level material requirements planning (MRP) systems and/or have been conducted under deterministic demand conditions. In these studies, nervousness is measured using various methods, in terms either of the frequency or the magnitude of changes in order quantity. The methods used in these studies were suitable for the particular operating environments that were being considered. Recently, a number of studies have been reported that evaluated schedule nervousness under more realistic conditions, such as in multi-level MRP systems under uncertain demand conditions. These studies have adopted some of the existing methods for measuring system nervousness. However, these methods do not capture all aspects of instability in multi-level MRP systems under uncertain demand conditions. In this article, we discuss the shortcomings of existing methods for measuring schedule nervousness, then present a new metric for measuring schedule nervousness in multi-level MRP environments. The proposed measure is illustrated by way of a detailed example. Results of simulation studies conducted to evaluate the effectiveness of the suggested method are also presented.