This paper considers an auto-correlated production process represented using a first-order auto-regressive model. During the period when the process is under statistical control, the mean values are contained in their objective value; after the occurrence of an assignable cause, a shift is produced. To detect the occurrence of the assignable cause, we propose a model of control charts with variable parameters to monitor the process and issue warning signals. The technical and economic success of implementing this tool depends on the adequate selection of parameters for the chart such as sample size, sample interval and the coefficient of the control limits. A cost-based model based on the Taguchi loss function was used to select the parameters and multi-objective optimization techniques on the response surfaces to find the optimal levels to minimize the cost and maximize the statistical potential of the chart. The fitting of the multiple regression models was necessary to assess the statistical and economic performance. Subsequently, we constructed a desirability function to simultaneously integrate the statistical and economic design. We identified and quantified the most significant design parameters and the effect of repetition. Finally, we reviewed the impact of the auto-correlation coefficient on the optimal selection of parameters. The results demonstrated that when considering an economic and statistical objective, the sample size is a significant variable in the monitoring of the process.@en

Chemical process and automation of data collection for industrial processes are known to result in auto-correlated data. The independence of observations is a basic assumption made by traditional tools that are used for the statistical monitoring of processes. If this is not adhered to then the number of false alarms and quality costs are increased. This research considers the use of variable parameters (VP) charts in the presence of autocorrelation. The objective is to determine the impact on the detection velocity and false alarms of different degrees of autocorrelation and their interaction with process conditions—the aim being to effectively select parameters. The VP chart showed improvements in its performance when detecting large average runs as the autocorrelation coefficient increased in contrast with the traditional variable sample interval (VSI) and x quality systems. This research demonstrates the superiority of variable parameters quality monitoring architectures over traditional statistical process monitoring tools.@en

The purpose of this article is to show the applicability and benefits of the techniques of design of experiments as an optimization tool for discrete simulation models. The simulated systems are computational representations of real-life systems; its characteristics include a constant evolution that follows the occurrence of discrete events along the time. In this study, a production system, designed with the business philosophy JIT (Just in Time) is used, which seeks to achieve excellence in organizations through waste reduction in all the operational aspects. The most typical tool of JIT systems is the KANBAN production control that seeks to synchronize demand with flow of materials, minimize work in process, and define production metrics. Using experimental design techniques for stochastic optimization, the impact of the operational factors on the efficiency of the KANBAN / CONWIP simulation model is analyzed. The results show the effectiveness of the integration of experimental design techniques and discrete simulation models in the calculation of the operational parameters. Furthermore, the reliability of the methodologies found was improved with a new statistical consideration.@en

Service industries have an important participation in the economies of developing countries and the advances achieved in their optimization are still incipient. This paper presents a new proposal for the life cycle of a service, having as starting point the dichotomy between a solution and the design. The results allowed to identify four macro-periods and within these, thirteen recurrent phases that permit to trace a generic service from its conception to the retirement, with the aim to open the possibility of implementing new support tools for its optimization and management. With this proposal it is possible to identify the items on which the efforts and controls should concentrate, so as to generate better services, more streamlined and of a higher value. This work is an effort to integrate the services to the global dynamics through a management model based on services.@en

The collection of data in the process can be done much faster and easier as a result of industrial automation allowing large amount of data for analysis. Because production processes are directed in part by inertial elements, if the data is collected at a higher rate, the observations will be auto-correlated. The violation of the data independence assumption causes an increasing in the false alarms rate and the quality costs of the traditional process monitoring tools. To mitigate this problem, we propose an economic-statistical design of a variable parameters control chart, also known as fully adaptive. The results show the effectiveness of this approach for the statistical monitoring of these processes. The "fully adaptive control charts" have been fairly evaluated in these scenarios, and are proposed as an important tool for the process monitoring under this circumstances.@en

There is a need to know the anthropometric parameters of each population to improve the ergonomic design of tools, workstations and personal protective equipment. In their regular work, humans use their hands to develop their activities, and the required equipment should match with the physical dimensions of the workers. The traditional manual method for measuring takes a long time because of the number of measures and the training of the measurer, who has to first learn how to take each measure, which is why the objective of the software is to diminish the time employed in the taking of the data by systemizing the process. This paper shows a compilation of 25 hand anthropometric measurements from a sample of 41 subjects from the Colombian Caribbean Coast. To take the measures, software was developed and validated with manually taken measures using the t-test for each dimension. The results showed that there was no significant difference between the two methods, which proves the precision of the software. The gather of more data employing the software may represent a reliable normative data set of the hand measurements.@en

Recent advances in the design of control charts have focused on variable parameters charts (VP) in which parameters are modified according to the last sample value. These charts have proved more effective in detecting assignable causes but more complexes for implementation in organizations. Although, there is a lot literature regarding the economic and/or statistical design of a VP chart, few authors focus their efforts on making them accessible to companies. In this paper a new procedure is proposed to reduce the complexity and enhance the benefits of an economic and an economic-statistical design of X charts with variable parameters.@en

This research contributes to assess the learning process of fire extinguisher training; which is an important analysis for the accurate design of training plans in order to ensure appropriate actions for fire mitigation. The experiment was executed using a fire simulator, 32 subjects participated in the trials for a month. In the results analysis, the data for each type of fire were adjusted with the Wright's Learning Curve model. The subjects' performance in the fire extinguishing training seems improved with experience, and the Wright's Learning Curve demonstrated been an effective tool to describe the process from a time/outcome perspective for each type of fire. On the other hand, the type C fire tends to have a more challenging learning process in contrast with the A and B types. Moreover, the results show the inadequacy of one-time training programs for fire extinguisher handling. Some future research recommendations are given.@en