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A structured approach for the reduction of mean time to repair of blast furnace D, ArcelorMittal, South Africa, Vanderbijlpark / Madonsela A.T.

Organizations are expected by their shareholders to continually deliver above
industry returns on capital invested and to remain competitive in the industry of
choice through productivity, safety and quality. The maintenance function is a key
area in which competitiveness through efficiencies and world–class performance can
be attained by focusing on the prevention and reduction of long and costly
equipment repair times.
The question is: how can the mean time to repair of equipment already installed in
the plant be reduced?
To answer the above question correctly and comprehensively, the research explored
mixed methods in finding answers. Quantitative methodology using a survey was
used for data collection. Observations and interviews were held with maintenance
personnel to uncover information that couldn’t have been obtained by means of a
survey.
The survey was limited to equipment performance measures, human factors,
environmental factors, planning, spare parts, maintainability, procedures and
training. To test consistency and accuracy of representation of the total population
under study, a reliability test was done by using Cronbach’s alpha coefficient. To
determine whether there are any differences between groups, an ANOVA test was
used. Cohen’s d–value was used to determine practically significant differences
between one set of data with another and correlation analysis was used to determine
the relationships between the variables.
The approach designed and delivered by this research flowed from the existing body
of knowledge, case studies and survey findings. The approach adopts some of the
elements of the failure mode and effects analysis (FMEA) procedure and differs from
other work that has been done by others by taking into account the competency and
experience of maintenance personnel and assigning to them factors which are used
to compute anew MTTR of the equipment. The cost of implementing the
recommended corrective actions for realising the new MTTR is determined and
evaluated against an improved equipment availability that will be achieved as a
result of the recommended corrective actions assuming that the failure rate of the
equipment remains constant. This evaluation step imbedded within the approach is
valuable for the maintenance function and management for decision making in
ensuring that resources at the organization’s disposal are used productively.
Validation and test results of the approach showed that the MTTR of equipment
installed in the plant can be reduced. The results also indicated that through the use
of the designed approach a regular pattern of repair or replacement times can be
followed well in advance and that it is practical, user friendly and it also delivers on
its objective of offering a structure for analysis and decision making aimed at
reducing the MTTR.
Included with this dissertation is feedback information that can be included in a
maintenance job card feedback section to capture information about factors that can
be improved to lower the MTTR as part of a continuous improvement process.
Included also is a spare part development and management procedure that can be
used by the maintenance function.
Recommendations on training of maintenance personnel on the maintainability of
equipment, the FMEA procedure and maintenance procedures are highlighted.
Information that flowed from this approach will be valuable for continuous plant
performance improvement and during the design, installation and operation stages of a blast furnace. / Thesis (M.Ing. (Development and Management Engineering))--North-West University, Potchefstroom Campus, 2012.

Identiferoai:union.ndltd.org:NWUBOLOKA1/oai:dspace.nwu.ac.za:10394/7311
Date January 2011
CreatorsMadonsela, Alex Thulani
PublisherNorth-West University
Source SetsNorth-West University
Detected LanguageEnglish
TypeThesis

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