DARPA ULTRALOG Final Report - Industrial and Manufacturing ...

architecture based on both the Grid and Web Service technologies. The Grid Service enables the
integration of resources and services across distributed, heterogeneous, dynamic virtual
organizations [3]. Cost and quality considerations may force large number of customers to look
for resources and services via such an architecture to deal with their own computing problems.
Ubiquitous computing technology embeds computers in various objects and places for sensing
and controlling environments [4]. As this technology is becoming realized and gives rise to
complex computing problems, the use of such an architecture might be inevitable.
In a grid service environment, a problem is processed by composing multiple resources and
services. As there can be several alternative compositions of resources and services for a given
problem, virtual markets will play a critical role in coordinating huge amount of economic
entities such as customers, service providers, and resource providers. There are various market
mechanisms such as OCEAN [5], Compute Power Market [6], and Nimord/G [7], proposed for
the large-scale virtual economy. However, one essential enabler of such markets is the ability to
agilely quantify the quality of service (QoS) achievable by each alternative. Without such a
capability, the alternatives cannot be valuated in a timely manner and the virtual economy will
fail to efficiently utilize the resources and services.
There can be various ways of defining QoS depending on the nature of the problems. We
consider a class of problems whose QoS is determined by completion time for generating a
solution. The completion time (also called makespan) is one of the most widely studied
objectives for diverse scheduling problems in the context of multiprocessor, manufacturing, and
project management. Regarding to problem solving structure we adopt component-based
architecture as a general framework. A component is a reusable program element. Component
technology utilizes the components so that developers can build systems needed by simply
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