Page 270 - Mechatronics for Safety, Security and Dependability in a New Era

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largely by knowledge and service contents, rather than just materialistic values in order to compensate
for volume reduction. Recently, leading scholars were calling for more research in the application of
engineering principles to the design and delivery of services, a research field that they called "service
engineering" (Tomiyama T., 2001).

A service is well defined in a framework consisting of a service provider, a service receiver, service
contents, and service channels. A service model consisting of three sub-models: scope model, view
model and flow model, is also presented. A computer-aided design tool, called Service Explorer, is
developed to represent a network of the parameters and determines the influence weight one another
(Shimomura Y., et al. 2003).

In this paper, we present a research framework for service engineering based on a kind of high-level
Petri Nets—Hierarchical Colored Petri Nets (Jensen. Kurt, 2004). Firstly we give the flow model in
top level net to describe the structure of a target service as a chain of agents existing in the service.
Then the sub pages corresponding to the substitution transitions of the top level net give the scope
models determining the sub services which include each agent as a receiver. Moreover, there are also
substitution transitions in the scope model, the sub pages corresponding to them give the view models
expressing the relationships among the RSPs (Receiver State Parameters), CoPs (Content Parameters),
and ChPs (Channel Parameters). Under this framework, we can represent material flow information,
also deal with RSPs. It will be helpful in intensifying, improving, and automating the whole service,
including service creation, service delivery, and service consumption. We illustrate the development
procedure by studying Consumer Electronics Rental Service using CPN—TOOLS software.

2. THE WHOLE STRUCTURE OF PRODUCING-CONSUMING SYSTEM AND THE TOP
LEVELPETRI NET

By "leasing" instead of "selling", Consumer Electronics Rental Service can realize a new paradigm
from product-selling to function-selling: reducing of cost and trouble of customers (buying, operation,
disposal), following customers' situation changes, taking back and renting again, tiding-up with house
leasing service with little customization instead of new needs for high functionalities.

The process from producing to consuming is a complicated and large system, obviously it is better to
describe it using hierarchical and modular method in order to analyze it clearly. We will deal with it
under the 3 sub-model framework and give a realization using Hierarchical Colored Petri nets.

Between the electronic producer (the service provider) and the consumers (the service receivers), there
are many intermediate agents, such as wholesalers, lease companies, and so on. They play different
roles and carry out relevant activities. Without considering the details about each activity, the
providing-receiving service relationship can be represented by flow model which is realized by the top
level net of HCPNs depicted as Figure 1. Where, a service provider is a place that has only outgoing
arcs; a service receiver is a place that has only incoming arcs; an intermediate agent is a place that has
both incoming arcs and outgoing arcs. The places of the top level net are all typed as E. By token e, we
can control the progress of the system. Transitions tl~t8 of the top level net are all substitution
transitions giving the scope models which determine the sub service activities.