Isabel da Silva Lopes

Prioritizing quality problems in SMEs: a methodology

Purpose – The purpose of this paper is to propose a new methodology to be used by small and medium enterprises to characterize their performance in quality, highlighting weaknesses and areas for improvement. The methodology aims to identify the main causes of quality problems and help to prioritize improvement initiatives. This is a methodology that intends to be easy to implement by companies with low maturity level in quality. Design/methodology/approach – Based on the literature review a methodology for diagnosing and prioritizing quality problems is proposed. Then two longitudinal case studies are performed to refine and validate the proposed methodology. The methodology is organized in six different steps which include gathering information about predetermined processes and sub-processes of quality management, defined based on Juran’s trilogy, and about predetermined results categories. Findings – The application of the methodology was successful in two case studies and a report was produced on the q...

Uncertainty Components in Performance Measures

Data quality is a multi-dimensional concept and this research will explore its impact in performance measurement systems (PMSs). Despite the large numbers of publications on the design of PMSs and the definition of critical success factors to develop Performance Measures (PMs), from the data user perspective there are possibilities of finding data quality problems, that may have a negative impact in decision making. This work identifies and classifies uncertainty components of PMSs, and proposes a qualitative method for PMs’ quality assessment. Fuzzy PMs are used to represent uncertainty that is present in any physical system. A method is also proposed to calculate an indicator of the compliance between a fuzzy PM and its target value, that can serve as a risk indicator for the decision-maker.

Classification methodology for spare parts management combining maintenance and logistics perspectives

Spare parts management is a function of maintenance management that aims to support maintenance activities, giving real-time information on the available quantities of each spare part and adopting the inventory policies that ensure their availability when required, minimizing costs. The classification of spare parts is crucial to control the vast number of parts that have different characteristics and specificities. Spare parts management involves mainly two areas, maintenance and logistics. Therefore, the integration of both input information is recommended to make decisions. This paper presents a multi-criteria classification methodology combining maintenance and logistics perspectives that intends to differentiate and group spare parts to, subsequently, define the most appropriate stock management policy for each group. The methodology was developed based on a case study carried out in a multi-national manufacturing company and is intended to be included in its computerized maintenance management syste...

State probabilities of a float system

Purpose – The purpose of this paper is to determine the state probabilities for a float system when overhauls are performed periodically.Design/methodology/approach – First, a model is developed to express the relationship between the rate of occurrence of failure and time interval between overhauls. Then, a methodology is defined to develop differential equations for each system state in order to calculate corresponding system state probabilities.Findings – Since it is considered that units requiring an overhaul stay in operation until replacement, the possibility of failure of those units has to be included. Then, the determination of system state probabilities has to be done iteratively.Practical implications – The methodology proposed in this paper enables comparison of different designs for a float system submitted to periodic overhauls through some different performance measures. System state probabilities can also be used to determine the idle time of units, which is essential to obtain the cost of...

Comparative Study of the Application of RCM and Risk Matrix for Risk Assessment of Collaborative Robots

This paper is focused on the study and analysis of risks associated with collaborative robots. Currently, collaborative robots are in full development with application in different sectors of activity. However, for these new working situations the adoption of suitable risk assessment approaches is necessary to deal with all new parameters and risks generated by the collaborative work involving a machine and human beings.

Performance assessment system development based on performance prism in social services

This paper aims to study the practical application of Performance Prism in the social services sector. To achieve this, a performance assessment system, based on the Performance Prism model, was developed in a Portuguese private institution of social solidarity.

Lean Six Sigma Project for Productivity Enhancement

The competitive market that companies are facing nowadays leads them to introduce frequently new products and, therefore, producing small series. This dynamic environment requires frequent changes in production lines and requires flexibility in the processes, which can cause reductions in the level of quality and productivity. This paper presents a Lean Six Sigma improvement project performed in a production line of the machining sector of a company from the motorcycles components branch. The project aims to eliminate losses that cause low productivity, affecting the fulfilment of the production plan, customer satisfaction and the increase of costs. The use of Lean methodology following the DMAIC phases allowed analyzing the factors that influence the line productivity losses. The major problems and causes that contribute to a reduction of productivity in the studied sector are the lack of standardization in the setup activities and the excessive stoppages for adjustment of the processes that caused an increase of defects. Quality tools such as control charts, Pareto analysis and cause-and-effect diagrams were used to analyze the problem. On the improvement phase of the DMAIC methodology, the reconfiguration of the line layout as well as the modernization of the process were the solutions chosen since their benefits justify their cost. The defective product units were reduced by 84 % and an increase of 29 % of line capacity was noticed.

Methodology for uncertainty characterization of performance measures

Purpose The purpose of this paper is to present a methodology to represent the uncertainty generated in performance measures (PMs) during the operational step or “use step” of the performance measurement process (PMP). The different steps of the methodology are described and exemplified through an application example. Design/methodology/approach An index that reflects the level of uncertainty originated by the factors and the strength of their inter-relationships is developed through the use of graph theory. A graph is developed considering all sources or factors of uncertainty that may be present in this process. Based on the graph, the methodology includes the use of a matrix and the determination of the associated permanent function which is used for determining the uncertainty index. Findings During the development of the methodology, it was found that the use of a scale that includes zero for assigning values of the elements of the matrix is not appropriate when using graph theory and permanent function calculation, since in this case the permanent function is insensible to changes in some matrix elements. Originality/value This paper identifies all the sources that can affect the quality of performance measurement values during the operational step of the PMP and proposes a method to characterize the strength of this uncertainty. Beyond alerting decision makers to the level of uncertainty associated with a PM, it also allows defining appropriate actions to improve PMs’ quality.

Survey on maintenance area of companies of the Manaus Industrial Pole

The study presented in this paper aims to identify the practices of maintenance organization and management adopted by companies in the industrial pole of Manaus in Brazil in relation to their production equipment. A questionnaire was developed and sent to the company of the industrial pole and the received data was analyzed using descriptive statistics. This survey shows that companies have several opportunities to make improvements related to maintenance management, such as adopting preventive culture, using adequate CMMS to support maintenance activities with associated failure analysis tools, and adopting meaningful KPIs.

Uncertainty characterization of performance measure: a fuzzy logic approach

The process of performance measurement encompasses the activities of designing, data collection and analysis. The lack of quality of performance measures (PMs) may influence decision-making. Since the process of performance measurement involves generally several actors, the decision-maker may not be aware of the level of uncertainty associated with performance measures. In this paper, fuzzy logic is used to represent the uncertainty generated in PMs during its design, use and analysis stages. The identification of uncertainty sources and the determination of an Uncertainty Index support actions to improve performance measures’ quality. An application example is provided to show the usefulness of the proposed methodology.