Table 2: Experimental results.
Case Algorith m
Data
fo r m o d e l
Data for
check
N um ber of
events (avg.)
N um ber of
unexpected
events (avg.)
N um ber of
expected next
events (avg.)
Fitness
A ppropriat
eness
1
H euristic M iner Log A (June) Log A (June)
2035.2 246.4 64.3 0.879 0.991
2
H euristic M iner Log A (June) Log B (July)
2054.7 273.5 64.8 0.867 0.991
3
P roposed algorithm Log A (June) Log A (June)
2035.2 93.7 75.2 0.954 0.989
4
P roposed algorithm Log A (June) Log B (July)
2054.7 122.1 76.4 0.941 0.989
latter are much smaller than the former. This results
in a higher value of fitness parameter for our
approach than for Heuristic Miner. Furthermore, the
numbers of expected next events and the
appropriateness values in both algorithms are almost
the same. Therefore, we can conclude that a more
precise model can be constructed through our
approach than through the Heuristic Miner algorithm
alone, without having much impact on the
appropriateness parameters.
In addition, the difference between the results
produced by the same algorithm (Case 3 and 4) is
quite small. Therefore, we can conclude that our
algorithm is able to predict the behavior of the job
nets in July using the model constructed from the
logs recorded in June with the same precision as in
the case where the log data used for model
construction and for conformance checking are the
same.
5 CONCLUSIONS
We proposed a job net mining method to derive the
execution order of job nets from their logs. In this
method, we identify the set of jobs executed at the
same time. Using this information, we then modify
the job net model derived by the Heuristic Miner
algorithm. Through conformance checking using the
log data of job nets executed in an actual SCM
system, we confirmed that our method enables
construction of a job net model that represents the
order relations between jobs more accurately and
appropriately than that obtained through Heuristics
Miner alone.
We are now considering the following work for
the future. First, we plan to develop methods for the
concise visualization of the structure and
characteristics of job nets. Since it is difficult for
system administrators (humans) to understand the
relationships between over 1000 events in a single
directed graph, we need a method of extracting the
important part of the model or abstracting its
structure in order to make it understandable.
Next, using the proposed approach, we plan to
develop a method of predicting the finishing times
of job nets. Since one of the biggest concerns many
administrators of job nets have is whether or not the
job nets will finish within the deadline, this function
will be able to help them manage their job nets more
efficiently.
Finally, we plan to develop a method for
analyzing the model derived by our approach. For
example, when failures or delays occur in job net
execution, the job representing the root cause can be
detected by backtracking through the order relations
in the derived model. In addition, by measuring the
execution durations of jobs, the critical path, taking
a large amount of time to finish, can be detected.
This information is useful for reorganizing job nets
so as to reduce their execution times. By these
analysis techniques, we will be able to improve
reliability in the management of large scale
integrated complex computer systems.
ACKNOWLEDGEMENTS
We would like to thank Masaru Ito for his help in
collecting job net data and for giving us much useful
advice.
REFERENCES
Fujitsu, 2008, SystemWalker Operation Manager v13.3,
http://www.fujitsu.com/global/services/software/
systemwalker/products/operationmgr/
Van der Aalst, W. M. P., Reijers, H. A., Weijters, A. J. M.
M., van Dongen, B. F., Alves de Medeiros, A. K.,
Song, M., and H. M. W. Verbeek, 2007, Business
Process Mining: An Industrial Application,
Information Systems, 32(5):713-732.
Van der Aalst, W. M. P., Weijters, A. J. M. M., and
Maruster, L., 2004, Workflow Mining: Discovering
Process Models from Event Logs, IEEE Transactions
on Knowledge and Data Engineering, Vol.16, No.9.
Van der Aalst, W. M. P., Alves de Medeiros, A. K.,
Weijters, A. J. M. M., 2005, Genetic process mining,
Proceedings of the 26th international conference on
PROCESS MINING FOR JOB NETS IN INTEGRATED COMPLEX COMPUTER SYSTEMS
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