Gianpaolo Di Bona

A-IFM reliability allocation model based on multicriteria approach

Purpose – The purpose of this paper is to evaluate reliability allocation using an aerospace system prototype. The proposed approach has been applied and compared with other traditional methods on an aerospace system prototype, where the reliability allocation process is rigorous. Design/methodology/approach – The new approach is based on integrated factors method (IFM), whose values are adjusted trough a multicriteria method, the analytic hierarchy process, depending on the importance of each factor and each unit of the system. The result is a dynamic model, that combines the advantages of the allocation method and the multicriteria decision-making technique. Findings – The reasons that led to the development of the IFM-based AHP are the outcome of a careful analysis of the current military and commercial approaches. In particular most of analyzed methods use constant weights for the factors involved in the reliability allocation; different weights are rarely assigned to these factors. Research limitatio...

Validation and application of a reliability allocation technique (Advanced Integrated Factors Method) to an industrial system

The proposed work analyses and applies a new reliability and redundancy allocation procedure. Starting from a similar methodology previously developed by the authors, Integrated Factors Method (IFM), a new reliability allocation and optimization method is developed: Advanced Integrated Factors Method (AIFM). The new technique has been proposed to analyze complex systems in the pre-design phase, even if its general characteristics allow extending the method to different design and production phases. The previous method has been improved through the introduction of new indexes that help improve underperforming components in order to achieve the allocated reliability values. The method introduces a big number of factors, so it can be applied to a wide range of systems. It is characterized by a very simple mathematical formulation, that can be made more complicated for a more detailed analysis.

Study and modelling of very flexible lines through simulation

The present paper proposes the development of a virtual model simulating an assembly line. Starting from the analysis of the real line, through an incremental approach, a simulation model is created, verified and validated, in order to obtain useful information about: • productive capacity; • partial and total lead time; • Percentage of saturation, Value Added (VA) and Non-Value Added (NVA), for each worker and station. During the development phase, an important goal has been pursued: the possibility to use and change the model without knowing the creation logic. It is possible to change input parameters through simple tables, which contain times of man-machine operations. You can easily set times in order to move an operation from one station to another or to add/delete a job in a station, according to the technological and ergonomic constraints of the process. Moreover, the acquisition of scheduling data is extremely easy and starts from the generation of a list of production codes related to different work-cycles.

AHP-IFM Target: An Innovative Method to Define Reliability Target in an Aerospace Prototype Based on Analytic Hierarchy Process

Reliability target definition is a crucial aspect of any reliability analysis. In literature, there are two types of analysis. The first one, called ‘bottom-up’, goes back to the systems target using data of units through a fault tree analysis. Reliability data of components could be only partially available, particularly in the case of innovative systems. In the second type of analysis, called ‘top-down’, starting from similar systems, the target of each unit is defined, by applying allocation techniques. Also, in this case, reliability data of similar systems might not be available, and the choice of the most appropriate technique could be tricky. The purpose of the present research is to combine the advantages of both usual approaches. The newly developed approach is based on the integrated factors method, whose values are adjusted trough a multicriteria method, the analytic hierarchy process, depending on the importance of each factor and each unit. The innovation of the proposed model consists in its dynamism, as most of the literature methods use constant weights for the factors involved in reliability allocation. No method takes into account the assignment of a different level of significance (weight) to different units of the system, simultaneously with the considered factors. The developed approach has been applied on an aerospace prototype system. The results show the goodness of the new method and its ability to overcome the problems noted in literature. Copyright

Maintenance strategy design in a sintering plant based on a multicriteria approach

Maintenance strategy design greatly contributes to ensure the pre-established production capacity of an industrial system and to reduce organisation cost, without compromising customer satisfaction resulting in loss of market share. The focus of the present research is a new model for maintenance policy developed and implemented in a case study. The new approach is focused on the adequate distribution of maintenance budget to system units according to the main factors determining availability and maintenance of equipment. These factors are summarised through appropriate indices, adjusted through a multicriteria method, the analytic hierarchy process (AHP), depending on the importance level of each considered factor and unit of the system. The results can be used as a support for allocation of budgets to maintenance activities, identifying machines or units that are strategic to ensure production. The model has been applied on a real industrial plant.

Assembly line balancing, proposal of a new methodology: integrated balancing method

In industrial plants, line balancing problems do not often find an objective solution and production managers often allocate tasks to operators without following a real methodology, but basing on personal experience; therefore, there are many problems when quick changes of capacity or constraints occur. The starting point of this study is the investigation of the main balancing methodologies, understanding their advantages and disadvantages in assigning homogenously tasks to workers. We propose new assembly lines balancing technique simple, general and effective, able to solve some ambiguity in balancing. Thanks to the proposed research, integration and a progress of classic methodologies have been realised. The method proposed, called IBM - integrated balancing method, has been applied to a real case study (the assembly line of a multinational company), in order to show its capacity of supporting production managers in designing and optimising assembly lines (ALBPs).

Building excellence through the Agile Reengineering Performance Model (ARPM): A strategic business model for organizations

The purpose of this paper is to build a theoretic and practical framework, based on agile project management, to support the decision-making process in order to help companies in optimizing the reengineering production processes and improve management costs.,This paper seeks to propose an agile Reengineering Performance Model (ARPM) for managing projects of reengineering of processes and applies it in a real case study concerning a water bottling plant.,The proposed model should serve as a valuable tool to facilitate a successful business process reengineering design in the project management and intends to assist companies as they operate projects of transferring and optimizing production lines. Thanks to the use of ARPM tools, it is easy to modify the evolution of the project, with the possibility of extending or enhancing the application if necessary.,The main limits of the ARPM model are: it requires close collaboration among team; it is rather intense for developers; and it is necessary flexibility to change course as needed and to ensure delivery of the right product.,The main implications of the authors’ work for research and business are to propose a structured methodological approach, rigorous but simple, suitable to implement in any companies.,The novelty of the approach is to apply the agile approach not for software development but in a manufacturing company.

Reliability Target Assessment Based on Integrated Factors Method (IFM): A Real Case Study of a Sintering Plant

The success of a company depends on customer’s satisfaction: quality, price, and service. These three goals depend in particular on R.A.M.S. characteristics: reliability, availability, maintainability, and safety. In the last few years, in order to guarantee high standards of reliability and maintainability, new methodologies and techniques have been developed to estimate the R.A.M.S. targets. In particular, the reliability target represents both the starting and the ending point of R.A.M.S. analysis. The design of the reliability target of a system is a crucial aspect of reliability analysis, as it affects the performance of the system and components. This paper aims to develop a new approach called “IFM Target,” to define the reliability target for complex systems through the integrated factors method, to combine the advantages of usually used approaches, and to overcome some criticalities highlighted in a careful literature analysis. The proposed method has been applied on a sintering system. The results show the effectiveness of the proposed approach.

Mathematical Models for Reliability Allocation and Optimization for Complex Systems

RAMS is an acronym for Reliability, Availability, Maintainability and Safety. These four properties concern the application of important methodologies for designing and managing complex technical systems. The present chapter analyses several reliability allocation techniques present in literature. Starting from well-known methodologies, two reliability allocation methods has been proposed and validated: Integrated Factors Method (I.F.M.) and Critical Flow Method (C.F.M.). We focus on the most important conventional methods to discuss their limitations to motivate the current research.

Total efficient risk priority number (TERPN): a new method for risk assessment

Safety is one of the most important issues in modern industrial plants and industrial activities. The Safety Engineering role is to ensure acceptable safety levels of production systems, not only to respect local laws and regulations, but also to improve production efficiency and to reduce manufacturing costs. For these reasons, the choice of a proper model for risk assessment is crucial. In this context, the present research aims to propose a new method, called Total Efficient Risk Priority Number (TERPN), able to classify risks and identify corrective actions in order to obtain the highest risk reduction with the lowest cost. The main scope is to suggest a simple, but suitable model for ranking risks in a company, to reach the maximum effectiveness of prevention and protection strategies. The TERPN method is an integration of the popular Failure Mode Effect and Criticality Analysis (FMECA) with other important factors in risk assessment.