of several types of asset replacement
policies that fall into the preventive
Listed below are some of the key attributes of the JITR policy:
Listed below are some of the key variants of the
Inspection-Based Replacement Policy:
There are some subtle, but important, distinctions
between JIT, CbR and IbR
Candidate Assets and Examples
Generally, this approach is best suited to assets that have the
Some examples of just-in-time replacement projects:
with highly predictable life cycles (ie., they are not stochastic).
with a narrow
with low impact of collateral
damage if failure is not
with short procurement lead times.
The replacement drivers for Just In Time Replacement
include the following:
- Replace the roof days before it starts
- Replace the fire alarm panel before the
replacement parts become obsolete.
Some of the merits of this approach are summarized below:
Some of the limitations of this approach are
- The owners extract the fullest possible
life out of the asset and avoid any opportunity cost of replacing the
asset early (ie., "reaching
- The owners enjoy the benefits of an optimal interval.
Mitigation - Mitigation of potential collateral damage.
Efficiencies - Reduced costs due to formal tendering
process well in advance of functional failure.
should not be confused with Run to Failure (RTF), where the latter
waits until failure
has occurred before taking action and the former tries to pre-empt
- This approach is particularly
challenging because it is difficult to predict the exact point of
functional failure of an asset as this requires a highly sophisticated
asset management team.
-- It requires a sophisticated asset management program which is both
labour intensive and capital intensive.
- This approach relies on detailed recordkeeping
of operating histories.
- This approach may expose the owner to some significant risk if an error
occurs in the anticipated timing of functional failure.
- Some assets have long lead times to procurement of replacement parts
so waiting until the last minute may be false economy.
- It is difficult to anticipate assets that are stochastic in nature.
below are some of the concepts to incorporate some of the principles of
Just-in-Time Replacement into the overall replacement strategy.
Fig. The two
classes of replacement strategies and summary explanation of the five
alternative replacement strategies.
A summary network diagram of the different asset replacement strategies
with Just-In-Time Replacement being one the preventive replacement
strategies under the Condition-Based sub-set.
replacement mapped onto the P-F curve to illustrate the relationship
with functional failure (F). Just-in-time replacement occurs as close
to point "F" as reasonably possible.
Examples of different types of asset replacement projects.