Evolução e avaliação da utilização do sistema Kanban e de suas adaptações: survey e estudos de caso

Abstract

This work departed from the finding that the changes occurred in the industrial competitive scenario are in conformity with the unfavorable conditions recognized for the use of the kanban system and that, due to this, the use of this well-known Systems for Coordination of Purchase and Production Orders (SCO) needs to be reviewed. Following, this research aims to evaluate the evolution of the utilization of the kanban system and study the adaptations made in its logic work to adjust it in face to the new conditions, and to evaluate the advantages and disadvantages of these adaptations. First of all, literature reviews regarding kanban system were made, and thirty three different adaptations were studied, classified and analyzed. It was found that, among other topics, the development of the adapted systems, in general, is in an initial stage, once the majority of the proposals are theoretical and might be considered to generate more appropriated practical forms. Afterwards, field research was realized, by means of a survey and case researches. In the survey, it was selected a non-probabilistic sample of thirty companies from São Paulo State that were implementing the kanban system in the beginning of the 90 s. It were identified 18 adaptations in practice in São Paulo State, however only 5 were analysed in the case studies. Among the 18 adaptations, 7 follow the logic of the original system and 11 do not. Thereby, it was proposed a procedure to evaluate the use of the kanban system in that industrial companies by means of the original work characteristics, production environment conditions and advantages of the system. The five adaptations analysed in the case studies have, as the main change, the utilization of only one type of signal or card. It was also concluded, by the use of the procedure, that the companies that use adaptations of the kanban system miss (in larger or smaller degree, depending on the adaptation) the following advantages: efficient production control; facility of problem causes identification; decrease of work in process; decrease of the lead-times; decrease of the waste; empowerment; simplicity of the administration mechanisms and efficient information control.