Lean manufacturing: costing the value stream

Purpose - The purpose of this paper is to identify the shortcomings of traditional cost accounting techniques in lean companies and then it seeks to analyse the validity and convenience of value stream costing (VSC) as a tool in a company that has adopted some concepts of lean manufacturing. Design/methodology/approach - The paper reviews the relevant literature in order to discuss the deficiencies of costing methods in lean manufacturing. It evaluates the requirements of VSC and provides a concrete illustration of VSC in the continuous improvement process of a point of sales terminal assembly line. Findings - The paper evidences the possible mistakes of cost accounting. The necessity and validity of VSC in lean manufacturing are presented, followed by a case example. In order to make continuous improvement decisions, VSM, VSC and box score offer complete information on the performance of the value stream. Research limitations/implications - Although accompanied by an application on a real case study, this is not an empirical investigation on the adoption of VSC. Practical implications - VSC requirements agree with the fundamentals of lean management. Therefore, VSC is a valid tool for lean companies, although the applicability depends on the maturity of the lean implementation. Originality/value - This paper contributes to the lean accounting literature because the management accounting literature still lags behind the lean transformation. This is one of the first papers on VSC in relevant journals and the first one to combine VSC and box scores with value stream mapping.Peer ReviewedPostprint (author's final draft

A stochastic approach for product costing in manufacturing processes

Nowadays, manufacturing companies are characterized by complex systems with multiple products being manufactured in multiple assembly lines. In such situations, traditional costing systems based on deterministic cost models cannot be used. This paper focuses on developing a stochastic approach to costing systems that considers the variability in the process cycle time of the different workstations in the assembly line. This approach provides a range of values for the product costs, allowing for a better perception of the risk associated to these costs instead of providing a single value of the cost. The confidence interval for the mean and the use of quartiles one and three as lower and upper estimates are proposed to include variability and risk in costing systems. The analysis of outliers and some statistical tests are included in the proposed approach, which was applied in a tier 1 company in the automotive industry. The probability distribution of the possible range of values for the bottleneck’s cycle time showcase all the possible values of product cost considering the process variability and uncertainty. A stochastic cost model allows a better analysis of the margins and optimization opportunities as well as investment appraisal and quotation activities.This work is supported by: European Structural and Investment Funds in the FEDER component, through the Operational Competitiveness and Internationalization Programme (COMPETE 2020) [Project nº 39479; Funding Reference: POCI-01-0247-FEDER-39479]

Mapeamento de fluxo de valor apoiado por sistemas de rastreio

Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia de ProduçãoA Manufatura Enxuta (ME), também conhecida como Sistema Toyota de Produção (STP), vem sendo utilizada por empresas do mundo inteiro, interessadas em buscar excelência em flexibilidade, qualidade, custos e desempenho na entrega. A ME apoia-se na utilização de um conjunto de práticas que visam alcançar estes objetivos, e o Mapa de Fluxo de Valor (MFV) tem-se mostrado como uma das suas práticas mais importantes. O MFV tem o objetivo de auxiliar as empresas no reconhecimento dos seus desperdícios, auxiliando na redução de custos e no aumento da produtividade e qualidade. Em estudos realizados sobre aplicações de MFV, identificaram-se alguns problemas que dificultam sua execução. Sua principal causa é a dificuldade na coleta de dados do processo produtivo, utilizados para construção de MFVs. De outra forma, a aplicação de tecnologias para rastreio vem crescendo de maneira expressiva, com a adoção de normas e padrões para o setor. Este trabalho tem o objetivo de desenvolver um método alternativo para coleta de dados utilizando equipamentos para georreferenciamento (GNSS), testá-lo na prática, e verificar se realmente pode servir como alternativa à coleta de dados para construção de MFVs. Este novo método, que pretende utilizar tecnologias de rastreio para construir MFVs, tem o objetivo de facilitar a coleta de dados em processos produtivos e tornar a execução dos mapas uma prática constante nas empresas.Lean Manufacturing (LM), also known as Toyota Production System (TPS) has been used by companies around the world, interested in pursuing excellence in flexibility, quality, cost and delivery performance. LM relies on the use of a set of practices aimed at achieving these goals, and Value Stream Map (VSM) has been shown as one of its most important practices. The VSM help companies in recognition of their waste, helping to reduce costs and increase productivity and quality. In studies about VSM applications, we identified some problems that hinder its implementation. Its main cause is the difficulty in collecting data from the production process, used for construction of FSMs. Otherwise, the application of technologies for screening is clearly growing, with the adoption of standards and industry standards. This work aims to develop an alternative method for data collection using equipment for georeferencing (GNSS), test it in practice, and make sure that it can serve as an alternative to data collection for construction of VSMs. This new method, you want to use tracking technologies to build VSMs, aims to facilitate the data collection processes and the implementation of the maps become a constant practice in companies

RFID-Enabled Dynamic Value Stream Mapping for Smart Real-Time Lean-Based Manufacturing System

Lean Manufacturing has become the most popular and dominant management strategy in the pursuit of perfection and in strengthening the competitive edges of manufacturers to face the challenges in the global markets. However, today’s global markets drive manufacturers to create highly customer-oriented job-shop manufacturing systems characterized by high dynamic behavior, uncertainty and high variability, in contradiction to lean being originally designed for high repetitive-production systems with a high-volume low-mix work environment with stable demand and a low degree of customization. Moreover, since the product is the changing agent, another challenging aspect that faces the effectiveness of lean is that the product life cycle is rapidly decreasing; and thus some of the lean initiatives often die after the product life cycle ends. In this regard, in order to constantly cope with the resulting rapid changes and adapt new process designs while reviving lean initiatives and keeping them alive; an effective real-time lean-based IT system should be developed, since lean without a real-time IT system has become impracticable and unthinkable in today’s high-customized manufacturing environments. In this context, due to the special characteristics and superior capabilities of Radio Frequency Identification technology (RFID), it could be the major enabler to support such a real-time IT system with real-time production data. However, RFID remains questionable and doubtable and manufacturers are still quite hesitant to adopt it in their manufacturing systems. This thesis introduces a solid basis for a standard framework of a digitalized smart real-time lean-based system. This framework describes the best practice of RFID technology through the integration of real-time production data captured via RFID with lean manufacturing initiatives in manufacturing systems, in order to overcome today’s lean manufacturing challenges. The introduced framework represents a new kind of smart real-time monitoring and controlling lean-based IT mechanism for the next-generation of manufacturing systems with dynamic and intelligent aspects concerning lean targets. The idea of this mechanism has been derived from the main concepts of traditional value stream mapping (VSM), where the time-based flow is greatly emphasized and considered as the most critical success factor of lean. The proposed mechanism is known as Dynamic Value Stream Mapping (DVSM), a computerized event-driven lean-based IT system that runs in real-time according to lean principles that cover all manufacturing aspects through a diversity of powerful practices and tools that are mutually supportive and synergize well together to effectively reduce wastes and maximize value. Therefore, DVSM represents an intelligent, comprehensive, integrated, and holistic real-time lean- based manufacturing system. The DVSM is proposed to contain different types of engines of which the most important engine is the “Lean Practices and Tools Engine” (LPTE) due to its involvement with several lean modules that guarantees the comprehensiveness of the real-time lean system. Each of these modules is specified to control a specific lean tool that is equipped with suitable real-time monitoring and controlling rules called “Real-Time Lean Control Rules” (RT-LCRs), which are expressed using “Complex Event Processing” (CEP) method. The RT-LCRs enable DVSM to smartly detect any production interruptions or incidents and accordingly trigger real-time re/actions to reduce wastes and achieve a smart real-time lean environment. Practically, the basis of this introduced framework in this dissertation is derived based on a highly customized job-shop manufacturing environment of an international switchgear manufacturer in Germany. The contributions of this dissertation are represented as follows: building the main framework of the DVSM starting with a systematic RFID deployment scheme on the production shop floor; introducing the main components of the DVSM (i.e. Event Extractor-engine, AVSM-engine, VVSM-engine, Real-time Rules-engine, and LPTE); demonstrating the feasibility of the DVSM concerning lean targets through developing a number of Lean Practices and Tools Modules that are supplied with RT-LCRs (e.g. Real-time Manufacturing Lead-time Analysis, Smart Real-time Waste Analysis, Real-time Dispatching Priority Generator (RT-DPG), Real-time Smart Production Control (RT-SPC), Smart-5S, Smart Standardized Work, Smart Poka-Yoke, Real-time Manufacturing Cost Tracking (RT-MCT), etc.); verifying the effectiveness of RT-LCRs in RT-DPG and RT-MCT modules through building simulation models using ProModel simulation software and finally proposing a framework of the tools “Smart-5S, Smart Standardized Work, Smart Poka-Yoke” to be implemented in the switchgear manufacturing environment

Wertstromdesign als Instrument der wertorientierten Unternehmensführung

Wertorientierte Unternehmensführung, Wertstromdesign als zentrale Methode des Lean Managements und die Flexibilität von Produktionssystemen haben sich als Managementansätze in der Vergangenheit bewährt. Die Koexistenz dieser Ansätze stellt Führungskräfte vor die tägliche Herausforderung, ihren jeweiligen Beitrag zur wertorientierten Unternehmensführung zu erkennen, operative Entscheidungen zu treffen und auf diese Weise die Wettbewerbsfähigkeit des Unternehmens im Spannungsfeld der Interessen der Anspruchsgruppen sicherzustellen. Unter der leitenden Forschungsfrage, welchen Beitrag das Wertstromdesign als Instrument der wertorientierten Unternehmensführung zum Unternehmenswert unter Beachtung der Flexibilität des Produktionssystems leistet, werden die Einzelkonzepte detailliert betrachtet, wesentliche Einflussgrößen sowie deren durch Reduktion von Komplexität entstehende Wechselwirkungen identifiziert und zur Handlungsorientierung methodisch gestützte Gestaltungsempfehlungen formuliert.:1 Einleitung … 1 1.1 Behandlung des Themas in der Literatur … 4 1.1.1 Wertstromdesign … 4 1.1.2 Flexibilität des Produktionssystems … 6 1.1.3 Wertorientierte Unternehmensführung … 8 1.2 Problemstellung und Zielsetzung … 11 1.3 Struktur der Arbeit und Vorgehensweise … 12 2 Theoretischer Bezugsrahmen … 15 2.1 Systemtheoretischer Ansatz zur Reduktion der Komplexität … 15 2.1.1 Begriffliche Abgrenzung und Arbeitsdefinition … 16 2.1.2 Ansatz der allgemeinen Systemtheorie … 17 2.1.2.1 Das Produktionssystem als Erfahrungsobjekt … 18 2.1.2.2 Der Wertstrom als Erkenntnisobjekt … 19 2.2 Wertstromdesign als Gestaltungsmethode … 20 2.2.1 Definition und Abgrenzung zu anderen Methoden … 20 2.2.1.1 Definition … 21 2.2.1.2 Abgrenzung zu anderen Lean-Methoden … 22 2.2.1.3 Abgrenzung zu anderen Prozessoptimierungsmethoden … 23 2.2.2 Vorgehensweise … 24 2.2.2.1 Festlegung der Produktfamilie … 24 2.2.2.2 Wertstromanalyse … 27 2.2.2.3 Wertstromdesign … 30 2.2.3 Zusammenfassung … 33 2.3 Flexibilität von Produktionssystemen … 34 2.3.1 Definition und begriffliche Abgrenzung … 34 2.3.1.1 Allgemeine Definitionen … 35 2.3.1.2 Abgrenzung von Agilität und Wandlungsfähigkeit … 37 2.3.2 Klassifizierung der Flexibilitätstypen … 39 2.3.2.1 Horizontale Klassifizierung … 39 2.3.2.2 Vertikale Klassifizierung … 41 2.3.2.3 Sonstige Klassifizierungen … 42 2.3.3 Messung der Flexibilität … 44 2.3.3.1 Zeit als Maß für die Flexibilität … 44 2.3.3.2 Kosten als Maß für die Flexibilität … 45 2.3.3.3 Wahrscheinlichkeit als Maß für die Flexibilität … 47 2.3.4 Zusammenfassung … 47 2.4 Wertorientierte Unternehmensführung … 48 2.4.1 Begriffliche Abgrenzung und Definition … 49 2.4.1.1 Shareholder-Value-Ansatz … 49 2.4.1.2 Stakeholder-Ansatz … 50 2.4.1.3 Arbeitsdefinition … 51 2.4.2 Wertorientierte Kennzahlenkonzepte … 52 2.4.2.1 Definition und Verwendung des Cashflows … 53 2.4.2.2 Discounted Cash-Flow (DCF) … 55 2.4.2.3 Shareholder Value Added (SVA) … 58 2.4.2.4 Cash Flow Return on Investment (CFROI) und Cash Value Added (CVA) … 59 2.4.2.5 Economic Value Added (EVA) … 61 2.4.3 Operationalisierung der wertorientierten Kennzahlenkonzepte … 63 2.4.3.1 Kennzahlensystem … 64 2.4.3.2 Werttreiberhierarchie … 64 2.5 Zusammenfassung … 65 3 Empirische Bestimmung von Wertstromtypen … 68 3.1 Modell zur Schätzung des Wertbeitrags durch das Wertstromdesign … 68 3.1.1 Bestimmung der Einflussgrößen … 69 3.1.1.1 Bestimmung der Erfolgsfaktoren und Kennzahlen … 69 3.1.1.2 Bestimmung der relevanten Flexibilitätstypen … 75 3.1.2 Konzeption des Modells zur Schätzung des Wertbeitrags … 76 3.1.2.1 Aufbau des Modells … 76 3.1.2.2 Ansatz zur Schätzung des Wertbeitrags … 78 3.2 Empirische Analyse zur Bestimmung von Wertstromtypen … 81 3.2.1 Datenbasis und Erhebungsmethodik … 81 3.2.1.1 Inhalt der Unternehmensbefragung … 82 3.2.1.2 Struktur der Grundgesamtheit … 82 3.2.2 Analyse der empirischen Datenbasis … 84 3.2.2.1 Gewichtung und Einfluss der Kennzahlen … 84 3.2.2.2 Faktorenanalyse … 90 3.2.2.3 Clusteranalyse … 94 3.3 Charakterisierung der Wertstromtypen … 97 3.3.1 Klassifizierungsmerkmale von Wertstromtypen … 98 3.3.2 Ableitung der idealisierten Wertstromtypen … 102 3.3.2.1 Cluster 1: Wertstromtyp „Balanced“ … 102 3.3.2.2 Cluster 2: Wertstromtyp „Pending“ … 03 3.3.2.3 Cluster 3: Wertstromtyp „Project“ … 104 3.3.2.4 Cluster 4: Wertstromtyp „Service“ … 105 3.3.3 .bersicht: Wertstromtypen … 106 3.4 Zusammenfassung … 10 4 Gestaltungsfelder des wertorientierten Wertstromdesigns unter Berücksichtigung der Flexibilität des Produktionssystems … 113 4.1 Ableitung der Gestaltungsfelder … 113 4.1.1 Gestaltungsansätze für die Haupteinflussgrößen … 113 4.1.1.1 Ansätze des Qualitätsmanagements … 113 4.1.1.2 Ansätze des Zeitmanagements … 16 4.1.2 Definition der Gestaltungsfelder … 117 4.1.2.1 Vier Gestaltungsfelder des wertorientierten Wertstromdesigns … 118 4.1.2.2 Einfluss der Gestaltungsmethoden auf die Flexibilitätsarten … 120 4.2 Gestaltungsfelder des wertorientierten Wertstromdesigns … 122 4.2.1 Fehlervermeidung … 122 4.2.1.1 Analyse der Fehlerrisiken im Ist-Wertstrom … 122 4.2.1.2 Reduzierung der Risiken im Soll-Wertstrom … 125 4.2.2 Fehlerabsicherung … 127 4.2.2.1 Fehleranalyse im Ist-Wertstrom … 127 4.2.2.2 Statistische Prozesskontrolle im Soll-Wertstrom … 130 4.2.3 Reduzierung der Komplexität … 134 4.2.3.1 Analyse der Produktkomplexität im Wertstrom … 135 4.2.3.2 Gestaltung eines wertstromgerechten Produktdesigns … 137 4.2.3.3 Analyse der Fertigungsorganisation … 139 4.2.3.4 Gestaltung wandlungsfähiger Fertigungssegmente …142 4.2.4 Stabilisierung und Optimierung des Prozesses … 144 4.2.4.1 Analyse des Informationsflusses … 144 4.2.4.2 Leitlinien zur Gestaltung des Material- und Informationsflusses … 146 4.2.4.3 Analyse der personalkritischen Engpässe … 148 4.2.4.4 Ma.nahmen zum Kapazitätsausgleich … 151 4.3 Zusammenfassung … 153 5 Fallstudien und Gestaltungsempfehlungen für das wertorientierte Wertstromdesign … 156 5.1 Auswahl der Fallstudien … 156 5.2 Ausgangssituation … 157 5.2.1 Fallstudie 1: Wertstromtyp „Balanced“ … 157 5.2.2 Fallstudie 2: Wertstromtyp „Pending“ … 62 5.2.3 Fallstudie 3: Wertstromtyp „Project“ … 65 5.2.4 Fallstudie 4: Wertstromtyp „Service“ … 168 5.3 Gestaltungsempfehlungen … 172 5.3.1 Wertstromtyp „Balanced“ … 172 5.3.2 Wertstromtyp „Pending“ … 174 5.3.3 Wertstromtyp „Project“ … 176 5.3.4 Wertstromtyp „Service“ … 177 5.4 Zusammenfassung … 180 6 Zusammenfassung und Ausblick … 183 7 Literaturverzeichnis … 18