José Luis Duarte Ribeiro

A framework for assessing the use of lean production practices in manufacturing cells

This study introduces a framework for assessing the use of lean production (LP) practices in manufacturing cells (MCs). The development of the framework included four stages: (a) defining LP practices applicable to MC, based on criteria such as the inclusion of practices that workers could observe, interact with and use on a daily basis; (b) defining attributes for each practice, emphasising the dimensions which were typical of their implementation in LP environments; (c) defining a set of evidence and sources of evidence for assessing the existence of each attribute–the sources of evidence included direct observations, analysis of documents, interviews and a feedback meeting to validate the assessment results with company representatives; (d) drawing up a model of the relationships among the LP practices, based on a survey with LP experts. This model supports the identification of improvement opportunities in MC performance based on the analysis of their interfaces. A case study of an MC from an automobile parts supplier is presented to illustrate the application of the framework.

MINIMIZING MANUFACTURING AND QUALITY COSTS IN MULTIRESPONSE OPTIMIZATION

Determination of the best operational settings for products or processes is usually accomplished through single-objective-function optimization routines, but in order to select the best design and operating control factors, all measures of quality must ..

Factors influencing knowledge transfer between NPD teams: a taxonomic analysis based on a sociotechnical approach

This paper sets out a taxonomy of the main factors influencing knowledge transfer (KT) between new product development (NPD) teams, based upon a sociotechnical approach whose framework consists of personnel, technological, work design, and external environment subsystems. The taxonomy was constructed from a literature survey combined with: (1) interviews and focus groups conducted with NPD experts and (2) a principal component analysis applied to a survey of 82 companies. Such steps were necessary because of the large amount of data collected from the literature review. They combine extensive explanatory descriptions from qualitative analysis together with strong confirmatory results given by multivariate quantitative analysis. The final set of 16 main factors summarized more than 100 elements of the NPD environment that influence KT between NPD teams. The key contributions of the proposed taxonomy are: (1) It is the first proposal of an organized understanding about KT influence factors based on a systemic and sociotechnical perspective; (2) New variables emerge from such analysis; and (3) It helps to understand better the elements needed for KT management in the NPD process.

Construção de indicadores para avaliação de conceitos intangíveis em sistemas produtivos

Este trabalho apresenta o desenvolvimento e a aplicacao de um metodo para a construcao de indicadores a fim de avaliar aspectos intangiveis de um sistema produtivo. Hoje em dia, principalmente nas organizacoes de servicos, os aspectos intangiveis tem sido usados na modelagem do sistema, no entendimento de problemas e na proposta e implementacao de estrategias. A partir da teoria das medicoes, que se baseia na filosofia da ciencia e na estatistica multivariada, foi elaborada uma abordagem para a modelagem teorica dos conceitos intangiveis de um sistema produtivo. A abordagem tem inicio com o mapeamento teorico das variaveis nao-manifestas, e continua identificando os construtos e o estado das variaveis, que pode estar relacionado a conceitos intermediarios, suportados por variaveis manifestas que podem assumir formatos categoricos, a serem pesquisadas por instrumentos apropriados, como os questionarios. Apos essas definicoes, o fenomeno em estudo pode ser representado por diagramas de caminho. Se o diagrama assume forma de arvore, a regressao multipla pode ser usada e a analise e facilitada. Se o diagrama assume forma sistemica, incluindo relacoes circulares, e necessario um tratamento matematico mais complexo, que foge do escopo deste trabalho. Uma aplicacao da abordagem proposta foi conduzida em quinze empresas de transporte coletivo de Porto Alegre, sendo mensurada a capacidade das empresas de apreender os conceitos de producao enxuta. Os resultados sao discutidos e sao apresentadas sugestoes para a continuidade dos trabalhos.

Cost–benefit analysis of a socio-technical intervention in a Brazilian footwear company

This article presents a costs-benefits analysis of a macroergonomic intervention in a Brazilian footwear company. Comparing results of a pilot line (composed by 100 multiskilled workers organized in teams) with eight traditional lines (still working in a one human being/one task model) the intervention showed to be worth pursuing since achieved gains were higher than intervention costs: there was a reduction in human resource costs (80% reduction in industrial accidents, 100% reduction in work-related musculoskeletal disorders or WMSD, medical consultations and turnover, and a 45.65% reduction in absenteeism) and production improvement (productivity increased in 3% and production waste decrease to less than 1%). The net intervention value of the intervention was around U

Identificação de oportunidades de pesquisa a partir de um levantamento da implantação da produção enxuta em empresas do Brasil e do exterior

430,000 with a benefit-to-cost ratio of 7.2. Moreover, employees who worked in the pilot line understood that their quality of work life improved, compensating the anxiety brought up by the radical changes implemented.

Influence of a programme of professional calibration in the variability of landmark identification using cone beam computed tomography-synthesized and conventional radiographic cephalograms

This paper presents a survey on the lean production (LP) implementation process in 47 Brazilian and foreign companies. Among the main results, the survey pointed out that the respondents are mostly interested in learning about lean organizational culture and value stream mapping. The main drivers for adopting LP are improving competitiveness and the fact that LP is adequate to solve critical production problems. People resistance to changes and difficulties to adapt concepts and practices are the main difficulties during LP implementation. The most frequently used practices are work standardization and visual management. Pull production implementation is the practice of highest priority. The results of this survey, along with the observation data collected during visits to some of the investigated companies, permitted the identification of research opportunities on LP implementation, which are summarized at the end of this article. Resumo: Este artigo apresenta um levantamento do processo de implantacao da Producao Enxuta (PE) em 47 empresas do Brasil e do exterior. Entre os principais resultados, o levantamento revelou que: os temas de maior interesse em ampliar conhecimentos sao a cultura organizacional enxuta e o mapeamento do fluxo de valor; os principais motivos para adotar a PE sao a necessidade de melhorar a competitividade e a adequacao da PE ao combate de problemas criticos da producao; as principais dificuldades na implantacao da PE sao a resistencia das pessoas e a dificuldade na adaptacao de conceitos e praticas; as praticas mais utilizadas sao a padronizacao do trabalho e o gerenciamento visual; a producao puxada e a pratica prioritaria no momento. Os resultados deste levantamento, aliados a observacoes realizadas durante visitas em algumas das empresas, permitiram a identificacao de necessidades e oportunidades para pesquisas sobre a implantacao da PE, as quais sao sumarizadas no final do artigo. Palavras-chave: Producao enxuta. Questionario. Avaliacao de empresas.

An integrative model for knowledge transfer between new product development project teams

OBJECTIVES The validity of any measurement obtained through a cephalogram largely depends on the reproducibility of the cephalometric landmarks. The purpose of this study is to evaluate the influence of a programme of professional calibration (PPC) on the variability of landmark identification comparing conventional radiographs and cone beam CT (CBCT)-synthesized cephalograms. METHODS 5 graduate students in oral radiology identified 20 cephalometric landmarks from cephalograms generated from conventional radiographs (RADs), Ray-Sum CBCT-synthesized cephalograms (CBTs) and half-skull CBT (HSTs) from 10 patients. After a period of reinforcement on instruction and calibration with inter- and intraexaminer assessment of reproducibility (intraclass coefficient correlation scores > 0.75) for RADs, CBTs and HSTs obtained from 5 different patients, observers were asked to repeat the analysis of the first 10 patients under the same circumstances. Values in millimetres represented each landmark in a table of Cartesian co-ordinates (x- and y-axes). RESULTS ANOVA showed significant reduction in variability levels after the PPC, and there were no differences among the methods of image acquisition. Repeated measures ANOVA indicated that the PPC accounted for reduction in variability levels in 14 of 20 landmarks. CONCLUSIONS The results suggest that a PPC has more influence than the type of image acquisition on variability of landmark identification based on two-dimensional cephalometric analysis. Cephalograms obtained from RAD or CBCT can be considered equivalent for clinical and experimental applications.

Previsão de demanda: uma aplicação dos modelos Box-Jenkins na área de assistência técnica de computadores pessoais

Knowledge transfer (KT) between new product development (NPD) project teams is considered by many authors as a process. A variety of works in literature have proposed models to elucidate such a KT process and its stages. However, the nomenclature used to describe these models and the proposed KT stages present large heterogeneity. Researchers from different fields have studied the KT processes; hence, there have been different interpretations or approaches for the same problem. This study presents a comparison of 14 KT models organized in two main research approaches: the emergent approach (which considers the dynamics and integration of the team) and the engineering approach (which considers the organization and management of knowledge). The comparison is based on content analysis. The main contribution of this paper is the proposition of a new model for KT between NPD project teams, integrating the previous models so as to provide a more complete and consistent KT framework.

Establishment of the optimal time interval between periodic inspections for redundant systems

Demand forecasting is an important tool to aid on the determination of necessary resources of a given company. In this paper, the Box-Jenkins methodology was applied to analyze historical data of a personal computer repair company and provide a forecast for the number of service calls. The company studied presents three segments of clients: contracts, warranty, and on-call. As each client has it own characteristics, in order to better represent tendency and seasonality behavior through the Box-Jenkins models, a specific forecasting model was developed for each segment. The choice of the optimum models were based into graphic analysis and statistical tests, which lead to the decision of adopting the AR(1) model to foresee the number of contract clients, the ARIMA(2,1,0) model for warranty clients and the SARIMA(0,1,0)(0,1,1)12 seasonal model for on-call clients.