Capturing provenance data in scientific workflows is a key issue since it allows for reproducibility and evaluation of results. Many of these workflows generate around 100,000 tasks that execute in parallel in High Performance Computing environments, such as large clusters and clouds. SciCumulus is a workflow engine for parallel execution in clouds. Activity failure is almost inevitable in clou...

Workflows are prevalent in diverse applications, which can be scientific experiments, business processes, web services, or recipes. With the dramatically growing number of workflows, there is an increasing need for people to search a workflow repository using keywords and to retrieve the relevant ones. A workflow hierarchy is a three dimensional object containing multiple abstraction views of d...

The type system of a language guarantees that all of the operations on a set of data comply with the rules and conditions set by the language. While language typing is a fundamental requirement for any programming language, the typing of data that flow between processing elements within a workflow is currently being treated as optional. In this paper, we introduce a three-level type system for ...

Although it is apparent that knowledge flows should be automated to improve efficiency and effectiveness of knowledge sharing with an organization, there exists no frameworks or systems designed specifically for such a purpose. While there are a number of systems that facilitate knowledge management, those systems do not support directly the modeling of knowledge workflows and their systematic ...

This paper presents the Bill of Experiments, a concept aiming at Knowledge Management of Scientific Experiments, representing knowledge about and used by scientific experiments; and a first prototype of its implementation. Experience drawn from environments for scientific and engineering software development and reuse suggests that this is a promising approach for scientific knowledge represent...

This paper presents a novel approach for the design and implementation of Grid Superscalar (GS) model on top of GWFE (Gridbus Workflow Engine). This new workflow-based version of the GS framework enables the easy development of applications (without the need of explicit expression of parallelism/distribution by the programmer) and scheduling them on Global Grids using the GSB (Gridbus Service B...

Agile workflow technology deals with business processes that require structural changes during run-time. For the difficult task of adapting the workflows, a modelling language that is easy to understand is essential. On the other hand, the workflow engine requires a workflow representation that can be processed, made persistent, and exchanged in a straight-forward way. XML provides a good means...

This paper addresses specification and implementation issues of workflow process compensation. The main consideration is to reduce the number of workflow activities that have to be compensated and re-executed when a failure occurs, as both can be very expensive. The main contributions of the paper are two-fold. First, we propose a flexible mechanism for specifying the compensation scope of a wo...

The event calculus is a logic programming formalism for representing events and their effects especially in database applications. This paper proposes the event calculus as a logic-based methodology for the specification and execution of workflows. It is shown that the control flow graph of a workflow specification can be expressed as a set of logical formulas and the event calculus can be used...

Often, real world business processes are constantly changing and dynamic in nature. These runtime changes may stem from various requirements, such as changes to the goals of the business process, changes to the business rules of the organization, or exceptions arising during the workflow execution. Unfortunately, traditional workflow management systems do not provide sufficient flexibility to a...