SKF Reliability Systems - Library

A RISK-BASED APPROACH TO PREVENTIVE
MAINTENANCE REVIEWS AT SYDNEY WATER
This paper describes a practical risk based approach to the Preventive Maintenance (PM) reviews and its
implementation in the computerised maintenance management system in Sydney Water (SWC). It discusses
the triggers for a PM review process at any specific plant or facility. This includes: Changes in operational
parameters impacting on the criticality of specific assets to the process, Measured lack of effectiveness of
current PM program, Identified PM job duplications or over-servicing issues, Increasing cost of failures &
increasing failure rates, Analysis of existing maintenance regime for appropriateness, Procurement of additional
assets / processes / systems or plants, Evidence of not enough PM’s carried out on critical assets.
This review process adopts a practical approach in documenting and addressing the business of operation
and maintenance, risk management, potential changes / modification and failure modes based on a joint
exercise between operations & maintenance. The changes / modifications to the Preventive Maintenance
schedules are then implemented in the Computerised Maintenance Management System (CMMS), which is
then available to Maintenance Delivery to carry out planned maintenance activities across mech/elec operating
assets within SWC. This approach ensures that more reliable assets are available to Sydney Water’s business
at an affordable cost.
SWC’S BACKGROUND
Sydney Water supplies more than 1.4 billion litres of water to more than 1.7 million homes and businesses
each day. About 80 per cent of our supply comes from the Warragamba Dam. We treat the water at 9 water
filtration plants and the largest plant at Prospect treats more than 80 per cent of our water. We then distribute
the water to our customers via our network of 266 service reservoirs, 148 pumping stations and nearly 21,000
kilometres of water mains.
Sydney Water collects and treats more than 1.2 billion litres of wastewater from homes and businesses each
day. Of this, we recycle more than 36 million litres each day. Our sewerage network services around 1.6 million
homes and businesses in the Greater Sydney region. Around 75 per cent of our wastewater is processed at
our three biggest plants at Malabar, North
Head and Bondi.
Sydney Water has a number of water
recycling schemes in place that help
reduce discharges of treated wastewater
to the environment and reduce demand on
water supplies. Use of recycled water is
approximately 25 billion litres a year. This is
expected to grow to 70 billion litres a year
by 2015.
Sydney Water provides stormwater services
to over 1.1 million people, servicing more
than 474,000 properties and 443 kilometres
of stormwater drains, which serve around
25% of metropolitan Sydney.
INTRODUCTION
G Orgil & N Marathe Sydney Water (Australia)
(A Paper Presented at ICOMS Asset Management Conference, Sydney 2009)
Where there is a desire to optimise
Preventive Maintenance (PM) for assets at a
plant or facility and where a comprehensive
Preventive Maintenance review cannot
be justified due to the resource intensive
nature of such an approach, a risk based
review of PM schedules may be used as
an alternative cost effective solution to
solve an immediate problem with a PM
Program. Sydney Water uses a systematic
combination of detailed maintenance
reviews and root-cause analysis to review
ACT
Monitor & Review
PM Effectiveness
and conduct a Post
Review Process (12
Month)
PLAN
Review Operational
needs, risk profile,
contingency plans,
system
redundencies etc
Check & Review
existing PM
Schedules and
document all PM
changes Job Plan
changes with
justification etc
CHECK & REVIEW
Figure 1 PM Review Process - Diagram 1
Carry out data
analysis of CMMS
data for existing
asset list, highlight
gaps and
update/modify.
DO