COMPUTING SCIENCE Resiliency Variance in Workflows with Choice

Computing a user-task assignment for a workflow coming with probabilistic user availability provides a measure of completion rate or resiliency. To a workflow designer this indicates a risk of failure, especially useful for workflows which cannot be changed due to rigid security constraints. Furthermore, resiliency can help outline a mitigation strategy which states actions that can be performed to avoid workflow failures. A workflow with choice may have many different resiliency values, one for each of its execution paths. This makes understanding failure risk and mitigation requirements much more complex. We introduce resiliency variance, a new analysis metric for workflows which indicates volatility from the resiliency average. We suggest this metric can help determine the risk taken on by implementing a given workflow with choice. For instance, high average resiliency and low variance would suggest a low risk of workflow failure. © 2015 Newcastle University. Printed and published by Newcastle University, Computing Science, Claremont Tower, Claremont Road, Newcastle upon Tyne, NE1 7RU, England. Bibliographical details MACE, C. J., MORISSET, C., AND MOORSEL, V. A. Resiliency Variance in Workflows with Choice [By] J. C. Mace, C. Morisset, and A. V Moorsel Newcastle upon Tyne: Newcastle University: Computing Science, 2015. (Newcastle University, Computing Science, Technical Report Series, No. CS-TR-1482)