![](bg8.png)
efficiently schedule the same number of workflows
using the proposed scheme than the greedy one.
Figure 2 shows the discrete efficiency value
denoted as
in (29) versus the number of tasks.
The efficiency decreases, however, peaks are
presented with a periodic order stemming from
round function in (29).
Finally, the gain, defined as the ratio of the
number of tasks over the minimum number of agents
required for achieving no overlapping versus
granularity is shown in Figure 3. It is clear that, the
gain is exponentially increases for low values of
granularity, instead of the high ones.
6 DISCUSSION
In this paper we propose a scheduling-oriented task
dispatching policy. The application context of the
suggested algorithm is WfMS where agents operate.
A major assumption that guided our approach is that
all agents are capable of executing all tasks (see
section 2.1). Apparently, this is not always the real
situation. To overcome this limitation, we may
integrate into the dispatching procedure a
negotiation step. During that step the manager agent
may call for bids and agents that fulfill the capacity
requirements may answer. Then the manager agent
can decide the allocation plan based on the available
agents. Another way is to incorporate broker agents.
Broker agents know the capacities of their teams, so
they could be in charge for the negotiation process.
Alternatively, the manager agent could dispatch
tasks to brokers, considering them as similar entities,
who in turn, will allocate their tasks to their agents.
Concluding, as simulations results demonstrate,
the task dispatching policy that we propose can
efficiently optimize both system’s performance and
user’s QoS requirements. Adopting optimization
criteria based on measures of task overlapping, we
approximate an NP-complete problem with an
algorithm of polynomial order. The results of our
algorithm can feed the workflow engines of a WfMS
system and allow them an adequate task allocation.
ACKNOWLEDGEMENTS
This work is supported by 03ED375 PENED
project, co-financed by 75% from E.U and 25%
from GRST.
REFERENCES
Aye, T., & Tun, K. M. L. (2005). A Collaborative Mobile
Agent-based Workflow System. Paper presented at the
6th Asia-Pacific Symposium on Information and
Telecommunication Technologies, 2005. APSITT
2005 Yangon, Myanmar.
Cao, J., Wang, J., Zhang, S., & Li, M. (2004). A
dynamically reconfigurable system based on workflow
and service agents. Engineering Applications of
Artificial Intelligence, 17(7), 771-782.
Debenham, J. (2002). Who does what in a multiagent
system for emergent process management. Paper
presented at the Ninth Annual IEEE International
Conference and Workshop on the Engineering of
Computer-Based Systems (ECBS' 02), Lund, Sweden.
Jennings, N. R., Norman, T. J., Faratin, P., O'Brien, P., &
Odgers, B. (2000). Autonomous Agents For Business
Process Management. Applied Artificial Intelligence,
14(2), 145-189.
Madhusudan, T. (2005). An agent-based approach for
coordinating product design workflows. Computers in
Industry, 56(3), 235-259.
Manmin, X., & Huaicheng, L. (1999). Cooperative
software agents for workflow management system.
Paper presented at the Fifth Asia-Pacific Conference
On Communications and Fourth Optoelectronics and
Communications Conference APCC/OECC '99,
Beijing, China.
Nakic, I., & Veselic, K. (2003). Wielandt and Ky-Fan
Theorem for Matrix Pairs. Linear Algebra and its
Applications, 369(17), 77-73.
O'Brien, P. D., & Wiegand, M. E. (1998). Agent based
process management: applying intelligent agents to
workflow. The Knowledge Engineering Review, 13(2),
161-174.
Qiu, J., Wang, C., & He, Y. (2005). Research on
application of intelligent agents in the workflow
management system. Paper presented at the 2005 IEEE
Networking, Sensing and Control, ICNSC2005,
Tucson, Arizona, USA.
Shepherdson, J. W., Thompson, S. G., & Odgers, B. R.
(1999). Decentralised Workflows and Software
Agents. BT Technology Journal, 17(4), 65-71.
Workflow Management Coalition. (1999). Terminology &
Glossary (WfMC Specification documents No.
WFMC-TC-1011).
Xu, Q., Qiu, R., & Xu, F. (2003, 5-8 Oct. 2003). Agent-
based workflow approach to the design and
development of cross-enterprise information systems.
Paper presented at the IEEE International Conference
on Systems, Man and Cybernetics, 2003. ,
Washington, D.C., USA.
Zur Muehlen, M. (2004). Organizational Management in
Workflow Applications – Issues and Perspectives.
Information Technology and Management, 5(3), 271-
291.
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