You are here:
Case Study Application of Determining End of Physical Life Using Survival Analysis (WERF Report INFR2R11b)
Citation:
Bourhill, M., W. Francisco, D. Jeong, AND D. Marlow. Case Study Application of Determining End of Physical Life Using Survival Analysis (WERF Report INFR2R11b). Water Environment Research Foundation, Alexandria, VA, 2014.
Impact/Purpose:
Benefits: This case study report (INFR2R11b) provides discussion on an application of selected advanced concepts included in the End of Asset Life (EOAL) Reinvestment decision-making process tool, to pumps and motors in the Milwaukee Metropolitan Sewer District, which: • Provides step-by-step process guidance to the asset management practitioner in making the cyclical transitional decisions between maintenance, operations and capital with a particular focus on the transition to capital reinvestment. • Assists the asset manager in determining which renewal strategy (maintenance/repair, refurbishment, replacement) is most cost effective and when in the life cycle of a given asset to transition from an operations and maintenance strategy to a capital reinvestment (renewal) strategy given a set of user established baseline conditions and assumptions.
Description:
Abstract: This case study application provides discussion on a selected application of advanced concepts, included in the End of Asset Life Reinvestment decision-making process tool, using Milwaukee Metropolitan Sewer District (MMSD) pump and motor data sets. The tool provides step-by-step process guidance to the asset management practitioner in making the cyclical transitional decisions between maintenance, operations, and capital with a particular focus on the transition to capital reinvestment. An application test team consisting of approximately seven key utility staff and four tool developers (consultants/academics) was formed to review application of the tool. MMSD volunteered to test the logic and application of the tool, and provided sewerage pumps and motors data. Senior staff from WERF joined the two-day application test team in applying the tool to MMSD’s data and business practices. The focus of the application of the tool was more on the usefulness of the decision logic rather than on data mechanics. While every step and task of the tool was “workshopped” with the application team over the two day period, due to time and financial data constraints the “hands on” application of the tool in the workshop invested more in introducing and testing the viability of the advanced concepts to determine the end of physical life. Determining the end of service level/capacity life and the end of economic life were also carefully illustrated and reviewed. This was the second case study of the End of Asset Life tool. The initial case study, which is addressed in a separate report (INFR2R11a), was conducted with Greater Cincinnati Water Works and Metropolitan Sewer District of Greater Cincinnati buried water and wastewater pipe assets. This document provides a brief overview of the End of Asset Life Tool in Chapter 1.0. Chapters 2.0 through 5.0 discuss the advanced method (survival analysis) in determining the end of physical life, survival rate of a pumps and motors at a specific age using the survival analysis method. [NOTE: The link below connects to a WERF site where the Final Report can be downloaded for free, after registering at the WERF site. For some projects the Executive Summary is available and can be downloaded for free without registering on the WERF site.]
