|Attributes of assets, systems or buildings
during the latter part/ stages of their respective asset life cycle.
is the final stage in the life of the asset where the owners are
challenged with finding a balance between maintenance, repairs and funding strategies for
the eventual replacement of the asset.
Late-life period is a relative concepts. For example, a
short-life asset (of say 10 years) will have a late life stage of
perhaps the years 7-10, whereas a long life asset (say 35 years) may
have an late life period of perhaps years 30-35.
Listed below are some of the key attributes of this life stage of assets:
Recognize that uncertainty is going to increase.
Determining the Arrival of the Late Life Stage
do we know that we have arrived at the late life of an asset. Listed
below are some of the techniques for making this determination:
These tables are generic and do not account for the unique exposure conditions at individual buildings.
The metrics will vary depending on the overall
life cycle pattern of the assets, which can be understood in terms of the following concepts associated with probability distributions and deterioration models:
What are the risk that arise at late life of an asset? These are the replacement drivers.
Late life metrics are necessary for the following asset management
principles, policies and strategies:
Listed below are some examples of different types of replacement policies.
- Do a risk evaluation. What will be the
consequences of the failure of the asset.
- Hire a Consultant. Determining
the arrival of the late-life stage of asset is a sophisticated process and will
vary by asset. The telltale signs and leading indicators are often subtle and nuanced,
requiring technical expertise on the intrinsic and extrinsic deterioration mechanisms
of the asset. It will therefore be
necessary to seek help from professionals to provide the strata with insight
into the factors that drive the replacement of the asset (such as physical
deterioration and technological obsolescence ). To provide the owners with insight into the factors that drive the replacement of the asset.
- Leading Indicators.
Telltale signs provides an early warning of an emerging condition,
which may takes months, years or decades to materialize fully. Leading
indicators are detected through a variety of means. Consultants use a
variety of diagnostic techniques to gather empirical information. Based
on the result of the diagnostic tests and visual inspections, the
strata will be provided with objective data to establish the lead times
to replacement. The necessary preparations can then be made to seek the
owners’ approval and raise funds.Commission leading indicator
diagnostics, such as thermography on the
assets to ascertain some leading indicators of telltale signs.
- Lead Times. Get to know the lead times to replacement of the assets. Significant lead time preparations are necessary to raise funds and seek owner approval
- Get familiar with the forces of retirement on the asset.
- The challenge of balancing the reaching life and extending life of an asset. During late life it is too late to extend life as that opportunity has passed.
- Balance of time-based and condition-based maintenance.
- The maintenance opportunities are limited during
the late life of an asset and the owners need to shift over to renewal planning.
- This is the stage at which the owners carry out a replacement analysis and develop a replacement policy.
- MRR Ratios. In some cases, it may be appropriate to start
holding back on some maintenance activities so that any savings can be diverted
towards replacement. Similarly, excessive monies being spent on repairs will
indicate that it is time to replace the assets. For example, a recirculating
pump may urgently need repairs and maintenance to prevent failure. However,
owners may choose to maintain the pump on a “run to failure” basis – that is, run
it without maintaining it. This will only be acceptable, however, if there is
little risk associated with failure of the asset and it will be more cost
effective to replace the asset than to maintain it.
- Unfunded Liability.
Depending on the level of reserve contributions over the life of the
asset, the strata will need to establish how the asset renewal project
will be funded by a combination of reserve transfer and special levy.
For medium and
long life assets, significant lead time preparations are necessary to raise
funds and seek owner approval. The asset may be replaced as a phased project.
Fig. The risk
spectrum extending along the P-F interval to illustrate the varying
strategies in the Pre-P and Pre-F periods. For example, a shift from
Time-Based Maintenance (TbM) to Condition-Based Maintenance (CbM).
Fig. Decisions should consider the whole life of assets, including the I-P interval and the P-F interval.
Fig. Early life, late-life and mid-life stages of an asset reflected on
the PF Curve.
Our cartoon character ("I. Care") is debating whether we can only
"reach" life or, in some cases, "extend" the service life of assets.
Fig. Illustration of a deterioration model for a roof system with distress metrics at different life stages.
Fig. Different types of maintenance activities at various life stages of an asset.