What we propose, and what would show us wrong.

Where the standards stop

ICMS 3 classifies and presents life cycle costs and carbon, and is free in full with its own Basis for Conclusions. Nothing requires a ratio quoted in a business case to say which ICMS categories it used, and widely quoted ratios such as 1:5:200 predate ICMS.

Why it earns its cost

The same building yields wildly different ratios depending on whether staff costs, renewals and end of life are inside the operating term, and over what period. A ratio without its three statements cannot be compared with any other ratio, which is usually why one is quoted.

Where the standards stop

IPSAS 45 paragraph 41 requires each part with a cost significant in relation to the total to be depreciated separately, which sets the minimum breakdown, and paragraph 8 declines to prescribe a unit of measure. The standard does not say how far beyond that minimum a breakdown should go, so an exercise run without a stopping rule has no natural end.

Why it earns its cost

The question that stops the exercise is not how deep the asset goes but how deep any decision goes. A component nobody will replace separately, price separately or rank for criticality is a row that costs money to create and to maintain and changes nothing.

Where the standards stop

IPSAS 45 requires an amount, a useful life, a residual value and a depreciation method. Paragraph 48 requires the useful life and the residual value to be reviewed at least annually, and paragraph 58 the method. The paragraphs cited here do not require any of the four to carry the reasoning that produced it. Application guidance AG27 sets a capability test for when an asset is available for use and does not say how capability is to be evidenced.

Why it earns its cost

A review of a figure whose basis was never written down can confirm that the figure has not changed; it cannot test whether the reasons for it still hold, which is what the annual review is for. The basis costs a sentence when somebody knows it, and is hard to reconstruct a year later.

Where the standards stop

ISO/TC 251’s guidance on the 2024 edition describes Clause 7.6, data and information, as clarifying how data and information differ and making its requirements clearer and more concise. It says nothing about a crosswalk. The row-level crosswalk is this publication’s proposal for making the correspondence between two registers demonstrable; its form and fields are not attributed to ISO.

Why it earns its cost

A shared key makes a lookup possible; it does not say how the two records relate. The financial register is coarser by design: one financial line can hold several maintainable items, and an item can sit in its own component or in the remainder. Their values can differ for good reasons, such as a depreciation life and a renewal interval set for different purposes. A crosswalk that states the correspondence, the accounting treatment and the reason for each difference lets a reviewer tell an intended difference from an error. A key alone does not.

Where the standards stop

The Saudi national turnover procedure (national project manuals, Volume 16) requires a warranty log to be available at turnover and the entity to designate a warranty administrator. The contractor’s obligation to remedy defects after taking over, and the period it runs for, are set by the contract: FIDIC 2017 Clause 11 and the Saudi procurement regulations. A supplier’s or manufacturer’s warranty is a separate document with its own period and its own start. Neither the procedure nor those contract provisions requires the conditions, the claim route or the ground of a refusal to be recorded.

Why it earns its cost

A supplier’s warranty starts on whatever event its own terms name, which need not be taking over, so a register that dates every warranty from handover can show cover that has already lapsed, or cover that has not yet begun. A warranty conditional on quarterly service by an approved agent is also a maintenance requirement, and it sits in a document filed at handover while the maintenance contract that has to satisfy it is often written by somebody who never saw it. A refusal states which condition the warrantor relies on; recording that ground on the row is what lets the maintenance arrangements be checked against it.

Where the standards stop

ISO/TC 251’s guidance describes Clause 7.7, new in the 2024 edition, as requiring the organisation to determine the knowledge needed to operate its asset management system, to have processes for dealing with it and to keep it current. FIDIC requires as-built records, which show what is there and not that it was meant to be different, or why. The list above is this publication’s proposal for what to capture; neither source sets it out.

Why it earns its cost

All four cost little on the day and are hard to recover once the site team has dispersed and the subcontractors have moved on. Without the as-left setpoints the first fault investigation begins by re-commissioning; without the approved departures, every future modification reopens a decision somebody already made carefully.

Where the standards stop

The Saudi Ministry of Finance publishes a useful life for 770 asset types and not one is a single figure; every one is a minimum and a maximum, printed beside a default life. Page 76 requires the entity to select useful lives within the published ranges, taking into account information from the manufacturer or its technical department, the nature of use and its ability to obtain the asset’s benefits, and to submit them for approval; it does not specify that the rationale for each selected point must be documented. The manual does not say what the default is for. IPSAS 45 paragraph 48 then requires the life to be reviewed annually.

Why it earns its cost

Across the 770 the maximum is a median 1.67 times the minimum, so the annual depreciation charge at the short end is a median 67% higher than at the long end and both are inside what the manual permits. A number that can move the charge by two thirds is a judgement large enough that its reasons belong beside it, and page 76 does not say that they must be.

Where the standards stop

ASHRAE reports the two separately and correctly, in columns headed "currently in service" and "replaced". A life table that gives a figure, or a range, without saying which population it came from cannot be checked against that distinction.

Why it earns its cost

Every unit in the in-service column is still running, so its age is a lower bound on its life, not an estimate of it. Averaging the two columns mixes lower bounds with completed lives, so wherever the replaced units lived longer than the survivors have so far, the pooled figure falls below the observed life. In the rows of ASHRAE’s cooling set with five or more replacements, pooling understates the observed life by between 22% and 42%. The error has a mechanism, and anyone can check it against the published columns.

Where the standards stop

The standards cited here do not set out how to build a renewal profile. ISO 55001 requires the activities that deliver the objectives to be planned and controlled, and says nothing about the arithmetic. ASHRAE publishes the dispersion, in the same table as the mean and in the same columns, and nothing requires anybody to use it.

Why it earns its cost

A hundred identical items on a point life produce a hundred renewals in one year and none in any other. At the standard deviation ASHRAE reports for the centrifugal chiller, 7.6 on a mean of 25.2, the same hundred items give about five in the peak year on a Weibull fitted to those two numbers, five on a normal and four treating every age in range as equally likely: the point calculation overstates the peak by 19.1, 19.7 or 26.3 times. The three agree because at this dispersion the shape hardly matters, which is the whole answer to the objection that the finding depends on a chosen curve. A bid for renewal funding built on the cliff asks for a spike nobody will fund and gets a number nobody believes.