공급네트워크 구조와 재고 비용 성과의 관계

박철순(Chulsoon Park),김성학(Sunghak Kim) 한국생산관리학회 2017 韓國生産管理學會誌 Vol.28 No.1

최근 공급 사슬을 네트워크 관점에서 바라보는 연구가 활발히 진행되고 있음에도 불구하고 아직까지 네트워크 구조와 성 과 간의 관계를 명확히 밝히는데 한계가 있었다. 우리는 이론적 배경을 바탕으로 공급네트워크의 성과가 공급네트워크의 구조에 따라서 달라질 수 있음을 가설로 제시하였다. 이를 검정하기 위해 공급사슬의 대표적인 모형인 비어게임을 네트워 크 형태로 확장한 행위자 기반 모형을 세우고 모의실험을 진행하였다. 구조화된 실험 설계를 통한 모의실험으로 얻은 방 대한 데이터를 분석한 결과 공급네트워크의 구조를 나타내는 지표 중 하나인 평균 경로 길이(average path length)와 성과 간에 역U자 관계가 있음을 밝혔다. 다시 말해, 공급네트워크의 참여 기업 간 논리적 거리가 가깝거나 먼 경우가 논 리적 거리가 중간 정도인 경우에 비해 공급네트워크 재고 비용이 낮게 나타났다. 나아가 이러한 구조와 성과의 역U자 관 계는 리드타임이 길수록, 단위당 재고 유지비용이 클수록 강화됨을 확인했다. 또한, 주문 정책에 따라 역U자 관계가 다르 게 나타남을 보였다. Although supply chain research with a network perspective has been growing fast recently, there are some limitations to verifying a relationship between supply network structure and performance due to the lack of data availability and the complexity of mathematical modeling. Based on a theoretical background, we propose a hypothesis that suggests a curvilinear relationship between supply network structure and performance. In order to test the hypothesis, we develop an agent-based model that extends the Beer Distribution Game from a serial chain to a complex network structure. The model considers different factors that may affect the supply network performance such as lead time, ordering policy, demand pattern, and product cost characteristics. Through deliberately structured simulation experiments, we develop a huge data set at the supply network level. The results show that there is an inverted-U relationship between the average path length (APL) of a supply network and its performance. In other words, supply network performance increases and then decreases as its APL increases. This means that we may achieve minimum supply network costs when the supply network structure is either centralized such as with a hub and spoke structure or decentralized as with a tree structure. Furthermore, the inverted-U relationship between structure and performance is moderated by lead time, ordering policy and unit inventory holding cost. As the overall lead time of supply network members increases or the unit inventory holding cost rises, the slope of the inverted-U shape steepens.

자동차 산업 공급 네트워크의 상류와 하류 구성 동인의 비교

박철순(Chulsoon Park) 한국생산관리학회 2024 한국생산관리학회지 Vol.35 No.1

Modern industry is a competition between supply networks. Knowing and managing the supply network well is an essential survival requirement for a company. There is a difference in orientation between the upstream and downstream of the supply network, which causes structural differences between the upstream and downstream. This study aims to reveal the differences in the configuration drivers of the upstream and downstream automotive supply networks. Using transaction data from the automotive industry, we compared the drivers that constitute supply networks and create upstream and downstream links. The Exponential Random Graph Models (ERGMs) were used to evaluate the significance of configuration drivers, including company attributes, dyadic attributes, and structural characteristics. As a result, the age of supplier, size of the purchaser, sales of the purchaser, asset of the purchaser, transitivity, and activity were found to be common drivers of upstream and downstream. On the other hand, the age of the purchaser, the difference in sales between the two companies, and popularity were found to be significant drivers only in the downstream network. These research results are the first to empirically compare the upstream and downstream supply networks, and have academic contribution as the first step in finding the cause of the differences in network structure between the upstream and downstream networks. 현대의 산업은 공급 네트워크 간 경쟁이다. 공급 네트워크를 잘 알고 관리하는 것은 기업의 필수 생존 요건이다. 공급 네트워크의 상류와 하류는 지향점에 있어 차이가 있고 이는 상류와 하류의 구조적 차이를 일으킨다. 본 연구는 자동차 공급 네트워크 상류와 하류의 구성 동인의 공통점과 차이점을 밝히고자 한다. 자동차 산업의 거래 데이터를 이용하여 공급 네트워크를 구성하고 상류와 하류의 링크를 만드는 구성 동인을 비교했다. Exponential Random Graph Model(ERGM)을 활용하여 기업의 속성, 양자 간 속성, 구조적 특성을 포함하여 구성 동인들의 유의성을 평가하였다. 그 결과, 공급처의 업력, 구매처의 규모, 구매처의 매출액, 구매처의 자산규모, 이행성, 활동성이 상류와 하류의 공통적인 구성 동인으로 밝혀졌다. 반면, 구매처의 업력, 양자 간 매출액 차이, 스타성은 하류 네트워크에서만 유의한 구성 동인으로 밝혀졌다. 이러한 연구 결과는 공급 네트워크의 상류와 하류를 처음으로 실증 비교한 것이며, 상류와 하류의 네트워크 구조 차이의 원인을 찾아내는 첫걸음이라는 학술적 의의가 있다.

중소 제조업의 개방형 혁신이 혁신 성과에 미치는 영향

박철순(Chulsoon Park) 한국생산관리학회 2012 한국생산관리학회지 Vol.23 No.3

본 연구는 중소 제조업의 개방형 혁신 노력이 혁신 성과에 미치는 영향을 살펴보았다. 특히, 개방형 혁신 노력과 혁신 성과 간의 관계를 개방형 혁신 파트너의 만족도가 조절하는지 2009년 중소기업 기술통계조사 자료를 바탕으로 실증하였다. 그 결과, 기업의 내부 혁신 노력과 개방형 혁신 노력 모두 혁신 성과에 긍정적 영향을 주는 것으로 나타났으며, 혁신 파트너와의 만족 수준에 따라서 개방형 혁신 노력이 혁신 성과에 미치는 영향은 다르게 나타났다. 특히 대학과 외국 기업과의 협력 만족도가 유의한 조절 효과를 가졌다. 또, 기업 수명 주기에 따라서 혁신 파트너의 조절 효과는 다른 것으로 확인됐다. 수명 주기의 네 단계 중 성장기와 구조조정기에서만 혁신 파트너의 조절 효과가 유효한 것으로 나타났다. Based on large-sample survey data of small- and medium-sized Korean manufacturing firms, we investigate the relationship between open innovation effort and innovation performance. Specifically, we address a research question whether there exist the moderating role of satisfaction of innovation partners on the relationship. Empirical findings using hierarchical moderated regression analyses suggest that both internal and open innovation effort increase innovation performance. In addition, we find that satisfaction with innovation partners moderates the relationship between the open innovation efforts and innovation performance. We further find that according to the corporate life cycle there is different significance of the moderating role of innovation partners satisfaction. Only at growth and decline stages, the satisfaction of innovation partners significantly moderates the relationship between open innovation efforts and innovation performance.

기업 간 협업 네트워크의 창발

박철순(Chulsoon Park) 한국경영과학회 2015 한국경영과학회지 Vol.40 No.4

This paper proposes relational capability as a main driver of constructing inter-organizational collaboration networks. Based on social network theory and relational view literature, three components of relational capability are constructed and implemented by an agent-based model. The components include organizational capability, structural capability, and trust between a partner and a focal firm. These three components are updated by two micro mechanisms: structural mechanism and relational mechanism. Structural mechanism is a feedback loop in which the relational capability increases structural capability and vice versa. Relational mechanism is a learning-by-doing process in which a focal firm experiences success or failure of collaboration and the experience increases or decreases cumulative trust in a partner firm. Result of agent-based simulation shows that a collaboration network emerges through interactions of firm’s relational capabilities and the characteristics of emerged networks vary with the contribution of structural capability and trust to relational capability. Specifically, in case structural capability contributes more to relational capability, the average degree centrality and collaboration proportion increases as time passes and enters into an equilibrium state. In that case, almost every firms participated in the network collaborates each other so that the emerged network becomes highly cohesive. In case trust contributes more to relational capability, the results are reversed. In an equilibrium state, the balance of contribution between structural capability and trust makes an emerged network larger and maximizes average degree centrality of the network.

대형 항공부품용 5축 가공기에서의 예측정비에 관한 연구

박철순(Chulsoon Park),배성문(Sungmoon Bae) 한국산업경영시스템학회 2020 한국산업경영시스템학회지 Vol.43 No.4

In the process of cutting large aircraft parts, the tool may be abnormally worn or damaged due to various factors such as mechanical vibration, disturbances such as chips, and physical properties of the workpiece, which may result in deterioration of the surface quality of the workpiece. Because workpieces used for large aircrafts parts are expensive and require strict processing quality, a maintenance plan is required to minimize the deterioration of the workpiece quality that can be caused by unexpected abnormalities of the tool and take maintenance measures at an earlier stage that does not adversely affect the machining. In this paper, we propose a method to indirectly monitor the tool condition that can affect the machining quality of large aircraft parts through real-time monitoring of the current signal applied to the spindle motor during machining by comparing whether the monitored current shows an abnormal pattern during actual machining by using this as a reference pattern. First, 30 types of tools are used for machining large aircraft parts, and three tools with relatively frequent breakages among these tools were selected as monitoring targets by reflecting the opinions of processing experts in the field. Second, when creating the CNC machining program, the M code, which is a CNC auxiliary function, is inserted at the starting and ending positions of the tool to be monitored using the editing tool, so that monitoring start and end times can be notified. Third, the monitoring program was run with the M code signal notified from the CNC controller by using the DAQ (Data Acquisition) device, and the machine learning algorithms for detecting abnormality of the current signal received in real time could be used to determine whether there was an abnormality. Fourth, through the implementation of the prototype system, the feasibility of the method proposed in this paper was shown and verified through an actual example.

개방형 혁신 네트워크의 동태적 모형

박철순(Chulsoon Park) 한국경영과학회 2015 한국경영과학회지 Vol.40 No.1

Literatures on open innovation have two major limitations. First, either on a firm level or on an industry level did they analyze the open innovation issues. The results of a firm’s innovation can be diffused through the whole network and the firm can learn back from the network knowledge. Prior literatures did not consider the feedback loop among firms and network in which the firms are involved. Second, most open innovation research had a static perspective on firm’s innovation performance. Since the diffusion, spill-over and learning among network members are involved over time, the open innovation is intrinsically dynamic. From the dynamic perspective, we can appreciate the fundamental attributes of the open innovation network which involves diverse firms, research institutes, and universities. In order to overcome the limitations, we suggest a dynamic model for open innovation network. We build an agent-based model which consists of heterogeneous firms. The firms are connected through a scale-free network which is formed by preferential attachment. Through the diverse scenario of simulation, we collect massive data on the firm level and analyze them both on firm and industry level. From the analysis, we found that, on industry level, the overall performance of open innovation increases as the internal research capability, absorptive capacity, and learning curve coefficient increase. Noticeably, as the deprecation rate of knowledge increases, the variability of knowledge increases. From the firm level analysis, we found that the industry-level variables had a significant effect on the firm’s innovation performance lasting through all the time, whereas the firm-level variables had only on the early phase of innovation.

보완적 혁신의 확산

박철순(Chulsoon Park),박상선(Sangsun Park) 한국경영학회 2014 經營學硏究 Vol.43 No.6

Many high-technology industry offers products or services which can be complemented by the other products, services, or contents. For example, the sales of a new digital device can be promoted by killer apps and a new application can penetrate market faster due to the wide-spread devices. It is called as “complementary innovation”. eBook industry is one of complementary innovations in which contents provider and terminal provider are complementers. Because of the complementarity among players, it is hard to predict the innovations diffusion and to suggest the market penetration strategy for each providers. Additionally, in a eBook industry, digital right management (DRM) makes the problems more complex. This article suggests an agent-based model for an eBook industry and brings several propositions based on simulation results. First, in a complementary innovation there exists a critical point of investment for software (or contents) provider that makes the market fail. In other words, unless the software (or contents) provider invest to push the appropriate quality of software (or amount of content) to the market, the market is saturated earlier with lower adoption rate. Second, in a complementary innovation the return on investment of the hardware provider diminishes. Therefore, there exists an optimum level of investment for the hardware provider. Finally, the effect of the digital right management on the diffusion of digital contents depends on the strategy of contents provider. Only when the contents provider pushes contents to market passively, the digital rights management can be effective in terms of high adoption rate and short payback period. This research shed little light on the penetration strategy for each player which participates in the complementary innovation.

ERGM을 활용한 자동차산업 공급 네트워크 분석

박철순(Chulsoon Park),강아롬(Ahrom Kang) 한국경영학회 2020 經營學硏究 Vol.49 No.1

This paper analyzes the endogeneous processes that make up the supply network of the automotive industry. A supply network is basically a network in which one company provides goods and information to another. The actual network we observe is a structurally emergent form in which several individual endogenous processes interact. The supply network is a complex adaptation system created by interaction processes. Nevertheless, previous studies have overlooked the interaction of these attributes or the endogenous processes. This is largely due to the limitations of existing research methodologies. Therefore, this study will examine the fundamental aspect of supply network as a complex adaptation system by using a new network analysis method that recognizes interactions in supply network. An Exponential Random Graph Model (ERGM) model was applied to the 2017 Automotive Handbook to explore the underlying processes of the supply network. An ERGM is an novel approach that incorporates endogenous structural effects of network and allows the interactions among various covariates of nodes or links. As a result, the supply network in the automotive industry was basically a chain structure. There were many types of chains that were supplied by suppliers to other companies after its own processing. The basic supply chain did not share intermediaries or skip tiers. In addition, it was difficult to find a structure that directly delivered to customers. In other words, there was no transitivity which can be easily observed in human networks. However, the more intermediaries they share, the more likely they are to have a direct trade relationship. In the case of the purchasers, we confirmed the phenomenon of the rich get richer, which is the possibility of additional transaction when receiving from various companies. As for the suppliers, it is revealed that the possibility of additional delivery is lower as they are delivered to various suppliers due to resource limitations. This study revealed for the first time the endogenous process that constitutes the supply network of the Korean automobile industry. The ERGM model, which recognizes the dependencies between explanatory variables, was used to analyze the fundamental processes of the automotive supply network. Comprehensive inclusion of various explanatory variables to identify the supply relationship in the automotive industry could lead to new conclusions, including the results of previous studies.

사출성형 공정에서의 통합정비방법에 관한 연구

박철순(Chulsoon Park),문덕희(Dug Hee Moon),성홍석(Hongsuk Sung),송준엽(Junyeop Song),정종윤(Jongyun Jung) 한국산업경영시스템학회 2015 한국산업경영시스템학회지 Vol.38 No.3

Recently as the manufacturers want competitiveness in dynamically changing environment, they are trying a lot of efforts to be efficient with their production systems, which may be achieved by diminishing unplanned operation stops. The operation stops and maintenance cost are known to be significantly decreased by adopting proper maintenance strategy. Therefore, the manufacturers were more getting interested in scheduling of exact maintenance scheduling to keep smooth operation and prevent unexpected stops. In this paper, we proposedan integrated maintenance approach in injection molding manufacturing line. It consists of predictive and preventive maintenance approach. The predictive maintenance uses the statistical process control technique with the real-time data and the preventive maintenance is based on the checking period of machine components or equipment. For the predictive maintenance approach, firstly, we identified components or equipment that are required maintenance, and then machine parameters that are related with the identified components or equipment. Second, we performed regression analysis to select the machine parameters that affect the quality of the manufactured products and are significant to the quality of the products. By this analysis, we can exclude the insignificant parameters from monitoring parameters and focus on the significant parameters. Third, we developed the statistical prediction models for the selected machine parameters. Current models include regression,exponential smoothing and so on. We used these models to decide abnormal patternand to schedule maintenance. Finally, for other components or equipment which is not covered by predictive approach, we adoptedpreventive maintenance approach. To show feasibility we developed an integrated maintenance support system in LabView Watchdog Agent and SQL Server environment and validated our proposed methodology with experimental data.

제조기업의 유연성과 성과 간의 관계

박철순(Chulsoon Park),박상선(Sangsun Park) 한국생산관리학회 2011 韓國生産管理學會誌 Vol.22 No.2

Using survey data of 193 firms from 22 manufacturing industries, we empirically show that manufacturing flexibility is composed of two hierarchical constructs: internal flexibility and external one. A structural equations model provides evidence that an organizational effort to improve the flexibility by a firm enhances the internal flexibility and this improves the external one sequentially. We also study the relationship between external flexibility and two dimensions of business performance – new product development(NPD) and financial performance. The results indicate that the external flexibility not only directly enhances the financial performance but does indirectly through the NPD performance, which confirmed the mediating role of NPD performance between flexibility and financial performance. Finally, we examine the moderating effect of an external variable(quality requirement level of market) on the relationship between manufacturing flexibility and business performances. The results suggest that NPD performance promotes financial performance in the higher level of quality-required market. 본 연구는 제조업의 생산유연성이 단계적으로 구분될 수 있는지와 조직차원의 노력이 어떠한 경로를 통해 생산유연성이 획득되는지를 실증적으로 확인하였다. 또한, 생산유연성이 기업의 여러 성과 차원과 어떤 관계를 갖고 있으며, 그 관계가 시장의 품질 요구 수준에 따른 조절효과의 영향을 받는지도 검증하였다. 본 연구의 대상은 제조업의 22개 업종, 193개의 기업이었으며 분석 결과, (1) 생산유연성은 내부와 외부 생산유연성으로 구분될 수 있으며, 내부 생산유연성이 외부 생산유연성을 향상시킴을 확인하였다. 또한, (2) 생산유연성을 높이려는 조직차원의 노력은 내부 생산유연성을 직접적으로 향상시키지만, 외부 생산유연성을 직접적으로 향상시키지는 않음을 확인하였다. 생산유연성과 성과 간의 관계에서는, (3) 생산유연성이 신제품개발 성과와 재무성과에 직접적인 영향을 미치며, 신제품개발 성과를 매개로 간접적으로 재무성과를 향상시킴을 확인하였다. 특히 (4) 신제품개발 성과와 재무성과간의 관계에 시장의 품질요구수준이 조절효과를 준다는 것을 실증하였다.