Integrated production quality and condition-based maintenance optimisation for a stochastically deteriorating manufacturing system

This paper investigates the problem of optimally integrating production quality and condition-based maintenance in a stochastically deteriorating single- product, single-machine production system. Inspections are periodically performed on the system to assess its actual degradation status. The system is considered to be in ‘fail mode’ whenever its degradation level exceeds a predetermined threshold. The proportion of non-conforming items, those that are produced during the time interval where the degradation is beyond the specification threshold, are replaced either via overtime production or spot market purchases. To optimise preventive maintenance costs and at the same time reduce production of non-conforming items, the degradation of the system must be optimally monitored so that preventive maintenance is carried out at appropriate time intervals. In this paper, an integrated optimisation model is developed to determine the optimal inspection cycle and the degradation threshold level, beyond which preventive maintenance should be carried out, while minimising the sum of inspection and maintenance costs, in addition to the production of non-conforming items and inventory costs. An expression for the total expected cost rate over an infinite time horizon is developed and solution method for the resulting model is discussed. Numerical experiments are provided to illustrate the proposed approach

A Longitudinal Study on the Effects of Network Capabilities of Firms and SME Policies

학위논문 (박사) -- 서울대학교 대학원 : 공과대학 협동과정 기술경영·경제·정책전공, 2021. 2. Jorn Altmann.South Korea's rapid growth from the 1970s to the early 1990s is largely due to the industrial structure centered on conglomerates that mainly export high-tech products with supports by the government. However, as the problem of the unbalanced industry structure emerged, support for SMEs has been strengthened, including SME-friendly public procurement policies. Public procurement in the software industry is also regulated by the Software Promotion Act, separate from the National Contract Act or the Procurement Business Act. A major issue pointed out in this public software procurement market was especially for conglomerates' extreme domination. Accordingly, the government has prevented conglomerates from participating in the public software procurement market since 2013, and prohibited multi-layered subcontracting practices from 2016. This study focused on the structural characteristics representing the network capabilities of firms, which have been frequently used in strategic management theory and organizational ecology, but difficult to systematically track dynamic changes over time. From 2008 to 2018, financial data of 2,665 major software firms with annual sales of more than 5 billion won and tax invoice transaction data had been consolidated. In the present study the effect of network capabilities on firm growth was dynamically analyzed, the net effect of the restriction system on participation of conglomerates (2013) on labor productivity was analyzed, and the net effect of the multi-layered subcontracting prohibition system (2016) on labor productivity and revenue growth was analyzed. As a result, it was found that integration, brokerage, and hierarchical trading network capabilities had a positive effect on revenue growth, but collaboration capabilities had a rather negative effect on the short term growth. In addition, in the software industry, unlike the manufacturing industry such as the automobile industry, the horizontal cooperation structure has a positive effect on productivity increase rather than the multi-layered vertical cooperation structure. Demand is important to the growth of a firm, but excessive measures such as excluding specific participants in a market may be poisonous to SMEs' productivity improvement and further growth. When creating a public procurement market environment that is the foundation for fostering target industries and firms, a government should concern not only the unique characteristics of the industry, but also the fact that roles and capabilities of firms are heterogeneous and their collaboration structure is important.한국의 집약적인 1970~1990년대 고도 성장은 정부가 조성하고 지원한 하이테크 제품을 주로 수출하는 대기업 중심의 산업구조 덕택이었다. 하지만 재벌에 편중된 산업 구조에 대한 문제점이 더 부각되면서 정부는 중소기업 친화적인 공공 조달 정책과 같은 중소기업 지원 정책을 강화해 왔다. 소프트웨어 분야 공공 조달 시장은 국가계약법, 조달사업법, 소프트웨어진흥법 등의 규율 하에 있는데, 그간 대기업의 독점적 참여가 중대한 이슈였다. 그에 따라 정부는 2013년부터 재벌 기업의 공공 소프트웨어 조달 시장 참여를 금지하고, 2016년부터 다단계 하도급을 금지하는 재 하도급 제한 제도를 실시했다. 소프트웨어 산업에서는 중소기업 뿐 아니라 모든 참여기업들의 협업 구조가 중요하기 때문에, 네트워크 역량을 나타내는 구조적 특성의 동태적인 변화를 면밀히 분석할 필요가 있다. 이를 위해, 이 연구는 2008~2018년까지 연 매출 50억 원 이상인 2,665개의 주요 소프트웨어기업의 재무 데이터를 구성했다. 또한 네트워크 역량을 구성하는 네 가지 지표를 조작적으로 정의하고 세금계산서 거래 데이터에 기초하여 분석한 후 통합 패널을 구축하였다. 그리하여 네 가지 서로 다른 네트워크 역량이 기업 성장에 미치는 영향을 동적으로 분석하고, 대기업 참여 제한 제도(2013)가 노동생산성과 수익성에 미치는 순 효과와 다단계 하도급 제한 제도(2016)가 노동 생산성 변화와 매출 성장에 미치는 순 효과를 분석하였다. 분석 결과, 통합·매개·계층적 거래 네트워크 역량은 연 매출 성장에 긍정적인 영향을 미치지만, 중장기적 협업 역량은 오히려 부정적인 영향을 미쳤다. 기업의 성장에 수요는 중요하지만, 해당 분야에 유효한 사업 권리를 갖고 있는 특정 기업군의 참여를 전면 제한하는 과도한 조치는 오히려 중소기업의 노동생산성 향상에 부정적인 영향을 미칠 수도 있다. 또한 소프트웨어 산업에서는 자동차 산업과 같은 제조업과 달리 수직적, 혹은 다층적 협력 구조 보다 수평적 협력 구조가 매출 성장에 보다 긍정적인 영향을 미친다. 산업과 기업 육성에 마중 물이 되는 공공 조달 시장 환경을 조성할 때, 우리는 산업 고유의 특성뿐 아니라, 기업 규모별로 역할 및 역량이 이질적이라는 점을 고려하여 사업의 기간 및 규모, 참여 기업 조건 등을 조화롭게 계획할 필요가 있다.Contents Abstract iii Contents vii List of Tables x List of Figures xii Chapter 1. Introduction 1 1.1 Research Background and Objectives 1 1.2 Outlines of the Overall Integrated Research Framework 3 Chapter 2. The Impact of Network Capabilities on a Firm's Growth 10 2.1 Literature Review 10 2.1.1 Penrosian Resource-Based View Theory 10 2.1.2 Organisational Economics Theory 11 2.1.3 Theory of Network Capabilities and Firm Performance 13 2.2 Research Model and Hypothesis 14 2.2.1 Operational Definition of Network Capabilities and Hypothesis Setting 14 2.2.2 Extended Model of Firm Growth 18 2.3 Variables and Data 23 2.3.1 Definition of Variables 24 2.3.2 Data 25 2.4 Result of Empirical Analysis 27 2.4.1 Descriptive Statistics 27 2.4.2 Analysis Result 28 2.5 Academic and Policy Implications 32 Chapter 3. The Policy Effect of Excluding Conglomerates' Participation on Labour Productivity of Target SMEs 36 3.1 Literature Review 36 3.1.1 Roles of the Korean Government: SME Policy and Public Procurement 36 3.1.2 Public Procurement and Firm Productivity 41 3.1.3 Public Procurement for Software Landscape Changes in Korea 43 3.2 Research Model and Hypothesis 47 3.3 Data and Analysis Method 49 3.3.1 Variables and Data 49 3.3.2 Analysis Method 52 3.4 Result of Empirical Analysis 55 3.4.1 Descriptive Statistics 55 3.4.2 Results of Analysis 56 3.5 Academic and Policy Implications 60 Chapter 4. Subcontracting Structure Matters: Innovation Performance in Software Industry 64 4.1 Literature Review 64 4.1.1 The Nature of Subcontracting 64 4.1.2 Software Industry and Multilayered Subcontracting Prohibition Policy 69 4.2 Research Model and Hypothesis 71 4.3 Data and Analysis Method 74 4.3.1 Variable and Data 74 4.3.2 Analysis Method 76 4.4 Analysis Results 80 4.4.1 Descriptive Statistics 80 4.4.2 Results of Empirical Analysis 81 4.5 Academic and Policy Implications 85 Chapter 5. Conclusion 89 5.1 Summary 89 5.2 Limitations and Future Research 96 Bibliography 98 Abstract (Korean) 117Docto

Reliability Modeling and Optimization Strategy for Manufacturing System Based on RQR Chain

Accurate and dynamic reliability modeling for the running manufacturing system is the prerequisite to implement preventive maintenance. However, existing studies could not output the reliability value in real time because their abandonment of the quality inspection data originated in the operation process of manufacturing system. Therefore, this paper presents an approach to model the manufacturing system reliability dynamically based on their operation data of process quality and output data of product reliability. Firstly, on the basis of importance explanation of the quality variations in manufacturing process as the linkage for the manufacturing system reliability and product inherent reliability, the RQR chain which could represent the relationships between them is put forward, and the product qualified probability is proposed to quantify the impacts of quality variation in manufacturing process on the reliability of manufacturing system further. Secondly, the impact of qualified probability on the product inherent reliability is expounded, and the modeling approach of manufacturing system reliability based on the qualified probability is presented. Thirdly, the preventive maintenance optimization strategy for manufacturing system driven by the loss of manufacturing quality variation is proposed. Finally, the validity of the proposed approach is verified by the reliability analysis and optimization example of engine cover manufacturing system

A review of discrete-time optimization models for tactical production planning

This is an Accepted Manuscript of an article published in International Journal of Production Research on 27 Mar 2014, available online: http://doi.org/10.1080/00207543.2014.899721[EN] This study presents a review of optimization models for tactical production planning. The objective of this research is to identify streams and future research directions in this field based on the different classification criteria proposed. The major findings indicate that: (1) the most popular production-planning area is master production scheduling with a big-bucket time-type period; (2) most of the considered limited resources correspond to productive resources and, to a lesser extent, to inventory capacities; (3) the consideration of backlogs, set-up times, parallel machines, overtime capacities and network-type multisite configuration stand out in terms of extensions; (4) the most widely used modelling approach is linear/integer/mixed integer linear programming solved with exact algorithms, such as branch-and-bound, in commercial MIP solvers; (5) CPLEX, C and its variants and Lindo/Lingo are the most popular development tools among solvers, programming languages and modelling languages, respectively; (6) most works perform numerical experiments with random created instances, while a small number of works were validated by real-world data from industrial firms, of which the most popular are sawmills, wood and furniture, automobile and semiconductors and electronic devices.This study has been funded by the Universitat Politècnica de València projects: ‘Material Requirement Planning Fourth Generation (MRPIV)’ (Ref. PAID-05-12) and ‘Quantitative Models for the Design of Socially Responsible Supply Chains under Uncertainty Conditions. Application of Solution Strategies based on Hybrid Metaheuristics’ (PAID-06-12).Díaz-Madroñero Boluda, FM.; Mula, J.; Peidro Payá, D. (2014). A review of discrete-time optimization models for tactical production planning. International Journal of Production Research. 52(17):5171-5205. doi:10.1080/00207543.2014.899721S51715205521

Contribution of offset to defence industrialisation in Indonesia

Offset is compensation given to a buyer country for an arms sale. Initially perceived as ‘necessary evil’ in an imperfect defence market, it now serves dual purposes: a marketing strategy for defence industry and a procurement policy for buyer country to generate add on benefits from arms import. Offsets proliferate, and so are stricter mandatory government policies. Still evaluation of offset has been difficult, mostly done in a country-based setting using anecdotal evidence that result in mixed findings. Following the issuance of mandatory offset policy in Indonesia through Law on Defence Industry in 2012, evaluation of past and current offset practice have become not only relevant but also critical to provide policy feedback. This dissertation provides an empirical examination on how offset has been understood and practised in Indonesia, and its contribution to defence industrialisation. The timeframe chosen is 1988-2014, when countertrade has been used to support the lifecycle of strategic industries: development (1988-1998), survival (1999-2009), and revitalisation (2010-2014). This study derives its validity and reliability from triangulation, comprising secondary data, survey, and case study. Three variables are analysed: technology development through ‘strategic industries’, defence offset, and defence industrialisation. Technology development focuses on how technology policy centred on a strategic industries paradigm and ladder of production to initiate industrialisation push. Defence offset discusses the conceptual and practical aspects of offset in Indonesia, including strategic objectives, regulation and institution frameworksin the defence procurement context, and offset life cycle and financing. Defence industrialisation discusses the impact of offset through employment, skill enhancement, transfer of technology, export promotion, domestic supply chain creation, and R&D. Field works were conducted in three firms representing different industrial sectors: PT DI (aerospace), PT Pal (shipbuilding), and PT Pindad (landsystem). Research findings indicate that, first, offset practice has mostly taken place on an ad hoc basis, with no clear reference to strategic objectives, as well as long-term management and financing- that mirror deficiencies in defence procurement. Second, as result of the deficiencies, offset results have been varied from one firm to another, across the different industrial sectors of aerospace, maritime, as well as ammunition and land system. While offset has a positive impact on skill enhancement and technology transfer, it seldom translates into new employment, supply chain creation, export, or R&D. This study generates the following recommendations. First, Indonesia needs to strengthen the management of offset through pre-offset planning and preparing practical guidelines for offset stakeholders in parallel with human resources to support the programme. This means identification of offset potential in procurement (convergence of long term technology policy and long term defence procurement plan), estimation of offset premium cost, allowing participation of industry in the early stage of the offset cycle, as well as devising methods of evaluating offset. Second, Indonesia needs to formulate strategic objectives for offset that relate closely to the dual purposes of defence modernisation and industry revitalisation. Third, Indonesia must strengthen the technology absorptive capability in industry in order to sustain the benefit of offset

Economic evaluation in decision models: a critical review and methodological propositions

International audienceDecision models of industrial management articles are often based on an economic criterion to find the proposed solution. They use economic parameters that are generally imported from the firm cost accounting system. When cost information is not adapted to the decision, the obtained solution of the model may be invalid. In this article, we deal with a critical literature review to report the methodological problems encountered in industrial management articles vis-à-vis the used costs. Finally we suggest methodological propositions to be kept in mind by authors when they are using costs in decision models