  Scientific workflows are powerful tools for management of scalable
experiments, often composed of complex tasks running on distributed resources.
Existing cyberinfrastructure provides components that can be utilized within
repeatable workflows. However, data and computing advances continuously change
the way scientific workflows get developed and executed, pushing the scientific
activity to be more data-driven, heterogeneous and collaborative. Workflow
development today depends on the effective collaboration and communication of a
cross-disciplinary team, not only with humans but also with analytical systems
and infrastructure. This paper presents a collaboration-centered reference
architecture to extend workflow systems with dynamic, predictable and
programmable interfaces to systems and infrastructure while bridging the
exploratory and scalable activities in the scientific process. We also present
a conceptual design towards the development of methodologies and tools for
effective workflow-driven collaborations, namely the PPoDS methodology and the
SmartFlows Toolkit for smart utilization of workflows in a rapidly evolving
cyberinfrastructure ecosystem.
