The proposed resilience analysis methodology and its application to the SaskWater pumping station
Resilience engineering first appeared as a new approach for both system design and system safety in the last decade. One of the first substantive publications on resilience as applied to engineering was “Resilience Engineering: Concepts and Precepts” [Hollnagel et al. 2006]. Hollnagel, Woods, and Leveson developed the basic concepts behind resilience engineering in order to understand and prevent tragedies such as the Columbia Challenger accident and the September 11 terrorist attack. In its present stage, resilience engineering has several fundamental problems. 1. There is not an appropriate definition for resilience. 2. The differences between resilience and other similar concepts are not clarified. 3. There is no quantitative method which can measure resilience. The three questions need to be addressed in order to advance the concept of resilience engineering and form a theoretical concept to an applied science. These three issues then form the foundation of this thesis. As a first step, a resilience definition is presented based on the concepts of system function and damage. Then, the differences between resilience and five similar concepts (reliability, robustness, repairing, redundancy, and sustainability) are clearly elaborated. As a last step, a method for quantifying resilience is proposed in the form of a resilience index. This method exclusively measures system resilience by analyzing the system recoverability from two points of view: reconfiguration and replacement of components. In order to illustrate the approach to and definitions of resilience, an actual application is considered: a water pumping station operated by SaskWater in Saskatoon, Saskatchewan (the Clarence Booster Station). This pumping station is a complicated system consisting of mechanical electrical and chemical subsystems. The resilience of Clarence Booster Station is analyzed using the proposed definition of resilience and resilience index. This thesis is just an initial step establishing a comprehensive definition (qualitatively and quantitatively) for resilience. The resilience index so defined in this work appears to have potential but much more scrutiny and refinement must be pursued to ensure that it is truly applicable to more universal engineering applications.
Resilience, Pumping Station, Recovery Process, Quantitative Measure
Master of Science (M.Sc.)