Reliability enhancement of manufacturing systems through functions

Abstract

A reliable system means being able to perform its intended functions. Therefore, ensuring performing of its required functions will help to enhance its reliability. For a manufacturing system (e.g. computer numerical control machines), there are a large number of functions, which complicate and make analysis difficult. In this article, a logical and systems approach of graph theory, which is effective to eliminate such difficulties, is employed. The graph theoretic models do consider the system structure explicitly and are applied to model functions at various hierarchical levels of a manufacturing system. These function digraph models are analysed using matrix approach to examine the cause and effect, which helps to evaluate importance of the function and hence provide direction for system reliability enhancement. A step-by-step methodology is presented, which is illustrated by an example of manufacturing system: computer numerical control drilling machine.

Degradation assessment of bearing based on machine learning classification matrix

“…Fault diagnosis of rolling element bearing was developed based on linear discriminant analysis and pattern recognition [32]. Two-dimensional visualization and classification accuracy of bearing data were showed to identifying different fault categories effectively.…”

“…Criteria: Severity of impact in the bearing degradation Catastrophic Any impact which could potentially cause the loss of primary system functions resulting in significant damage to the mechanical system and cause the loss of life Critical Any impact which could potentially cause the loss of primary system functions resulting in significant damage to the mechanical system and negligible loss to life Degradation Any impact which degrades system performance functions without appreciable damage to either mechanical system or life Healthy Any event which could not cause degradation of system performance function(s) resulting in negligible damage to mechanical system Graph theoretic model was considered the system structure explicitly and applied to model functions using matrix approach to examine the cause and effect. Result showed the reliability enhancement using step-by-step methodology [32]. Structural graph model for reliability at various hierarchical levels was developed by converting reliability graph into equivalent matrix [33].…”

Reliability analysis of the precision assembly process of a scaled stator can of the AP1000 reactor coolant pump

“…In order to reduce the faults rate of the rotor system, the reliability of a rotor system with two kinds of common faults (oil whip and resonance) was discussed by Su et al. 15 Loganathan and Gandhi 16 use a systems approach of graph theory to analyse the reliability of manufacturing systems that have a large number of functions. Because tool reliability has a significant impact on the machining efficiency and financial cost in the cutting process, Cui et al.…”

“…To improve the performance of casting machines from the design phase and the exploitation period, Desnica et al 14 use the failure modes and effect analysis method to assess its reliability. In order to reduce the faults rate of the rotor system, the reliability of a rotor system with two kinds of common faults (oil whip and resonance) was discussed by Su et al 15 Loganathan and Gandhi 16 use a systems approach of graph theory to analyse the reliability of manufacturing systems that have a large number of functions. Because tool reliability has a significant impact on the machining efficiency and financial cost in the cutting process, Cui et al 17 discussed the reliability of the ceramic tools under the work condition of continuous-interrupted turning of hardened steel.…”

Failure Evaluation and Analysis of Mechatronics-Based Production Systems during Design Stage Using Structural Modeling

“…Soft computing approaches [7] have been employed for carrying out FMEA (Failure mode and effects analysis) on production systems. In a recent work, functions have been considered for reliability enhancement of complex production machines [8].…”