Introduction to maintenance and safety management, definitions of key terms are presented here.

1. Dr. Nafis Ahmad
Professor
Department of IPE, BUET
Email:nafis@ipe.buet.ac.bd
AEM-6235 Maintenance
and Safety Management

2. Topics
▷ Introduction
▷ Maintenance Management and Control
▷ Preventive Maintenance
▷ Corrective Maintenance
▷ Reliability Centered Maintenance
▷ FMEA
▷ Safety and Maintenance
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6. 1.
Introduction
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7. Introduction (Maintenance)
• Since the Industrial Revolution, maintenance of engineering
equipment in the field has been a challenge. Although impressive
progress has been made in maintaining equipment in the field in an
effective manner, maintenance of equipment is still a challenge due
to factors such as size, cost, complexity, and competition.
• Today’s maintenance practices are market driven, in particular for the
manufacturing and process industry, service suppliers, and so on. An
event may present an immediate environmental, performance, or
safety implication.
• Thus, there is a definite need for effective asset management and
maintenance practices that will positively influence critical success
factors such as safety, product quality, speed of innovation, price,
profitability, and reliable delivery.
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8. Introduction (Maintenance)
• Each year billions of dollars are spent on equipment
maintenance around the world.
• Each year over $300 billion are spent on plant maintenance
and operations by U.S. industry, and it is estimated that
approximately 80% of this is spent to correct the chronic
failure of machines, systems, and people.
• Annually, the cost of maintaining a military jet aircraft is
around $1.6 million; approximately 11% of the total operating
cost for an aircraft is spent on maintenance activities.
• The typical size of a plant maintenance group in a
manufacturing organization varied from 5 to 10% of the total
operating force: in 1969, 1 to 17 persons, and in 1981, 1 to
12 persons.
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9. Introduction (Safety)
 The desire to be safe and secure has always been an
intimate part of human nature since the dawn of human
history.
 The demand for safety and security is pursued at every
location in one’s entire environment. This ranges from
homes, in transit, at all premises, and indeed in the
workplace.
 8% of US workers suffer accident each year in
workplaces. In 1996, in US 3.9mil disabling injuries, 4800
death and cost was estimated $121 billion.
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10. Maintenance Terms and Definitions
▷ Maintenance: All actions appropriate for retaining
an item/part/equipment in, or restoring it to, a given
condition.
▷ Maintenance engineering: The activity of
equipment/item maintenance that develops
concepts, criteria, and technical requirements in
conceptional and acquisition phases to be used and
maintained in a current status during the operating
phase to assure effective maintenance support of
equipment.
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11. Important Terms and Definitions
▷ Preventive maintenance: All actions carried out on a
planned, periodic, and specific schedule to keep an
item/equipment in stated working condition through the
process of checking and reconditioning.
▷ Corrective maintenance: The unscheduled
maintenance or repair to return items/equipment to a
defined state and carried out because maintenance
persons or users perceived deficiencies or failures.
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12. Important Terms and Definitions
▷ Predictive maintenance: The use of modern
measurement and signal processing methods to
accurately diagnose item/equipment condition during
operation.
▷ Maintenance plan: A document that outlines the
management and technical procedure to be employed
to maintain an item; usually describes facilities, tools,
schedules, and resources.
▷ Reliability: The probability that an item will perform its
stated function satisfactorily for the desired period
when used per the specified conditions.
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13. Important Terms and Definitions
▷ Maintainability: The probability that a failed item will
be restored to adequately working condition.
▷ Active repair time: The component of downtime
when repair persons are active to effect a repair
▷ Mean time to repair (MTTR): A figure of merit
depending on item maintainability equal to the mean
item repair time.
▷
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14. Important Terms and Definitions
▷ Overhaul: A comprehensive inspection and restoration
of an item or a piece of equipment to an acceptable
level at a durability time or usage limit.
▷ Inspection: The qualitative observation of an item’s
performance or condition.
▷ Maintenance person: An individual who conducts
preventive maintenance and responds to a user’s
service call to a repair facility, and performs corrective
maintenance on an item.
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15. Important Terms and Definitions
▷ Safety: Condition of being free from or protected against
failure, damage, error, accidents, or harm or any other event,
which could be considered undesirable.(wiki) Safety in a
system is defined as quality of a system that allows the system
to function under predetermined conditions with acceptable
minimum of accidental loss.
▷ Hazard: Any existing or potential condition in the workplace
which can result in the unwanted effects of death, injuries,
property damage, or other losses. Lack of safety occurs due to
existence of hazards.
▷ Stimuli: Set of events or conditions that transforms a hazard
from its potential state to one that causes harm to the system,
related property or personnel. A trigger is needed to convert a
hazard to an accident. This trigger is known as stimuli.
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16. Important Terms and Definitions
▷ Stimuli: Set of events or conditions that transforms a hazard
from its potential state to one that causes harm to the
system, related property or personnel. A trigger is needed to
convert a hazard to an accident. This trigger is known as
stimuli.
▷ Accident: Dynamic mechanism that begins with the
activation of a hazard and flows through a system as a
series of events, in a logical sequent, to produce a loss.
▷ Accident is the outcome of a hazard that is triggered by a
stimuli. An accident happens when there is loss of plant
system or part of the system, injury to or fatality of the
operators or personnel in near proximity, and property
damage of related equipment or hardware
▷
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17. Conclusions
▷ Whenever a machine stops, it incurs cost. Production
pressure in manufacturing industries is high. Question:
Production or Maintenance?
▷ When breakdown occurs, everyone looks for maintenance
fault. However when factory runs smoothly no one want to
give credit to maintenance dept.
▷ In following lectures maintenance and safety issues will be
discussed in detail.
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18. Thanks!
Any questions?
You can find me at:
@ahmadn
nafis@ipe.buet.ac.bd
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