wilamowski-b-m-irwin-j-d-industrial-communication-systems-2011

Semantic Web Services for Manufacturing Industry 65-9
65.3.4 Optimization
The process flows are represented as network flow graphs representing all the data and process dependencies.
A cost will be associated with each branch of the graph representing the cost of the process
in the real world. All constraints including resource constraints and dependencies will then be represented.
Given that some of these could be linear or even perhaps nonlinear, the network flow optimization
methods used in [Sjelvgren 83] can be used for the optimization of the problem. The methods have
been shown to capable of dealing with problems with over 20,000 variables and limited sets of nonlinear
constraints and currently constitute the most widely used methods worldwide by the power industry for
medium term optimization of hydrothermal systems.
65.3.5 Data, Process and Timing Consistency and Conformance
The model proposed in this chapter utilizes Colored Petri Net (CPN) [Jensen 96], which will enable
us to represent processes and subsystems involving complex preconditions, multiple threads of execution,
and allow the use of guards to enforce security conditions. The CPNs also have clearly defined
semantics. As they are a high level Net that allows folding of the Net, this helps deal with the problem of
dimensionality and allows scaling up of the model. CPN is the high level Petri net, which allows for the
representation of the multilevel behavioral abstractions through place/transition refinements. It allows
the use of colored tokens, complex predicates associated with transitions, and the use of guards to control
the enabling of transitions before firing. The advantages include avoiding cluttering the diagrammatic
representation with excessive formalism.
This approach has four characteristics on the encoding: (1) events with associated pre/post-conditions,
(2) individual methods that are activated to service events, (3) flow of control and data within the system,
and (4) interactions between the controlled component processes and the interface, including the
instance data and method. In contrast, the domain-specific behavioral aspects relate to the sequencing
of events and the satisfaction of the pre- and post-conditions related to a specific service interface at the
right point in the sequencing. The authors have previous experience at modeling FMS systems using
high-level Petri nets [Zurawski 92] and Inter Object Interactions using CPNs [Hanish 97].
65.3.6 Customer-Centered Design through the Concept of Customer Value
It is important in the design of the systems and techniques that there is not only a manufacturer, constructor,
and developer view embedded in the system, but also a customer-centered view. We intend to
incorporate this customer-centered view through the use of the notion of customer value and also to
carry out the setting up of the case studies incorporating these ideas of customer value.
The approach in this chapter is vital to the manufacturing and construction industries in which there are
severe shortages, and in the IT industry in the area of ontology engineering. This is evidenced by the enormous
number of unfilled academic positions and also the lack of quality project managers in industry. This
is particularly the case where multisite production is being widely carried out in Australia and worldwide.
65.4 Conclusion
In this chapter, we proposed a reconfigurable multisite production system supported by a number of key
emergent technologies: Semantic Web (i.e., ontology architecture), Web 2.0, and Web services technologies.
The proposed solution aims to solve two key issues during the manufacturing processes: customization
of products and multisite production. This enables a modern manufacturing system to carry out
manufacturing and assembly to varying levels of granularity at multiple sites and to create major product
components through the assembly of subcomponents sourced from different producers or factories
in a highly flexible manner.
© 2011 by Taylor and Francis Group, LLC