Q2. What is the advantage of using Web services?
One of the advantages of using Web services is to enable easier and greater interoperability and integration among systems and applications.
Q3. What is the main advantage of QoS analysis?
As workflow systems carry out more complex and mission-critical applications, QoS analysis serves to ensure that each application meets user requirements.
Q4. What is the primary goal of using a database system loosely coupled with the workflow system?
One of the primary goals of using a database system loosely coupled with the workflow system is to enable different tools to be used to analyze QoS, such as project management and statistical tools.
Q5. What is the second class of information used to describe the QoS of a task?
The second class, the distributional class, corresponds to the specification of a distribution function which statistically describes tasks behavior at runtime.
Q6. What is the approach to predicting performance of a WfMS?
Their approach is based on continuous-time Markov chains and Markov reward models to predict the performance, availability, and performability of a WfMS under a given load.
Q7. What is the purpose of the re-computation of QoS estimates for tasks?
The re-computation of QoS estimates for tasks and for transition probabilities is done based on runtime data generated from past workflow executions that have been stored in the database log.
Q8. What is the probability used to compute workflow QoS?
The values specified in the basic class are typically employed by mathematical methods in order to compute workflow QoS metrics, while the distributional class information is used by simulation systems to compute workflow QoS (Chandrasekaran, Silver et al.
Q9. What is the expected effect of the SWR algorithm on the reliability of the DNA Sequencing?
it is expected that as the workflow system executes more instances, the reliability of the DNA Sequencing workflow will decrease.
Q10. How long does a task wait for a transition to be enabled?
A task t remains in the pre-init state as long as its task scheduler is waiting for another transition to be enabled in order to place the task into an initial state.
Q11. What is the method used to re-compute the probabilities of a workflow?
When instances of a workflow w have already been executed, then the data used to re-compute the probabilities come from initial designer specifications for workflow w, from other executed instances of workflow w, and if available, from the instance of workflow w for which the authors wish to predict the QoS.
Q12. What is the cost associated with the execution of a workflow task?
Task cost (C) is the cost incurred when a task t is executed; it can be broken down into two major components: enactment cost and realization cost.