4.3.2.1
When to Use Approaches Other than Condition-Based Management
Condition-based management requires a commitment to reliable asset condition information. The necessary level of effort is not likely to be appropriate for some assets. Some assets do not lend themselves to management using a traditional condition-based management approach. The five most common reasons assets do not fit a condition-based approach are as follows:
- The assets do not have a typical life cycle – This group of asset classes includes rock slopes or other perpetual features that do not have predictable deterioration patterns.
- The assessment of condition or performance may not be feasible – The most common type of assets in this second group are geotechnical or utility assets for which many elements may be buried or otherwise inaccessible. The absence of a rating methodology may also drive the management of assets using something other than a condition-based approach.
- The life cycle is driven by factors other than condition – There are many assets that are replaced when they are worn out or obsolete. Technology assets, which are susceptible to obsolescence at a frequency similar to their functional service lives, are examples of assets that fall into this category.
- The assets have long service lives and the failure of individual assets presents limited risks to safety or system performance – Examples of these asset classes include guardrail, gravity retaining walls, or highway lighting.
- The performance expectations require the asset to remain in near-new condition. For safety-critical assets, replacement may be necessary before signs of deterioration are evident. This is most common in risk-averse industries such as aviation. However, contractual arrangements, such as in public-private partnerships (P3), may require condition or performance targets that warrant a life cycle management approach other than condition-based.
As discussed earlier, assets that fall in these categories are typically managed using an interval-based approach or a reactive approach. Some agencies also use a risk-based approach for certain types of assets, such as rockfall management. These three different approaches are briefly explained, and examples are provided for each approach.