The Asset Reinvestment Logic Diagram End of Asset Life Reinvestment Decision Support Tool

Setting the platform for “Business Rules” Integrate operational level performance statements and capacity limits with tolerable risk levels to set stage for “Business Rules” A business rule is a statement that articulates what actions are to be taken if a certain set of conditions are met. The sequencing of the various steps from beginning to end is depicted in business logic. Together they first, facilitate selecting those assets that meet certain trigger conditions and, second, provide for what is to happen once the triggers are met. Setting the trigger points can be guided by tolerable risk concepts. For example, where consequence associated with a specific asset failure is high, the condition score at which intervention action is to be considered can be lowered (for example, from an 9 to a 7) so that the probability of acting before unplanned failure occurs is higher. Examples of relevant business rules are presented in the following slide. “Business Rules” End of Asset Life Reinvestment Decision Support Tool

Set up “end of service level/capacity life” business rules Relate strategic level LOS to operational level asset performance in measurable terms Identify “service life” assets: “cannot/should not fail” and “low tolerable risk” assets (e.g. assets where failure of the asset leads directly to failure to sustain service levels/performance standards and which are of such high consequence of failure that they are deemed “cannot fail” or “low risk tolerance” assets) Identify assets reaching capacity limits Set up “business rules” that operationalize LOS/Capacity statements Minimum condition score (i.e. “condition score no greater than 6”) Maximum risk score (“BRE score not to exceed 64”; “risk cost < $500k”) Number of failures/unit of time (i.e. “no more than 3 breaks in five years and no more than 5 breaks over lifetime”) Design storms for wet weather peak limits Since end of service level/capacity life is defined by LOS / asset performance parameters, these business rules constitute “triggers” or “tripwires” for reaching the end of service level/capacity life! End of Asset Life Reinvestment Decision Support Tool

Thought exercise 1 – create service level/capacity business rules Mini-Exercise What would you need to know to create service level/capacity business rules for: A sewer lift station? A water main? Develop two rules for each (list assumptions) Consider: Is the asset a high consequence of failure asset (e.g. is it a “cannot fail” or “low risk tolerance” asset)? What is an appropriate risk tolerance level trigger for that asset? At what level is the trigger tripped? For both assets it would be important to know the risk profile (probability of failure, consequence of failure, risk score) and the most imminent primary failure mode, the condition/performance score of the asset, and the asset performance requirements for each (design peak load, projected flow, required fire flow, etc). Examples of business rules would include: If condition equals 7 or greater, flag for attention. If projected peak wet weather flow exceeds X cfs in next three years, flag for attention. If number of breaks is greater than 4 over past five years, schedule for replacement. End of Asset Life Reinvestment Decision Support Tool