1. Introduction

UCRAV (Collaborative Use of High Value Resources in Spanish) is a platform for remote instrumentation services, built with a set of open code tools, designed for Internet (among them the Globus Toolkit for the construction of Grid services).

The UCRAV platform is a Grid -distributed computing application- for research and scientific-technologic development. As for the service, it allows for the remote visualization of analyses performed by scientific instruments located in various institutions and via UCRAV's Grid it created and promotes a collaborative ambience between researchers and users.

2. Workflow System and Remote Instrumentation

Workflow management is very important to carry out experiments remotely conducted. The reason is very simple: when remotely working on samples' analyses data cannot be managed locally (in the researcher's workstation), since they need to be copied in the storage centre (data base) of the instrument to be used for them to be shared between researchers (user and instrument operator) in a collaborative environment.

A workflow can be defined as a construction which describes how information is exchanged between different actors -within the context of an application developed for the remote use of an instrument-, and which indicates the temporary dependencies, as well as other types of dependencies.

Essentially, a workflow shows how the tasks within a process are structured, which activity comes after another and which activity retrieves the entry of the other one.

Within the Grid context, Workflow languages are necessary since the components of applications are lightly coupled and, typically, are (re-) composed to create new applications based on the same structural blocks.

To understand the platform's functioning, see: UCRAV's Workflow Model.