Page 150 - Mechatronics for Safety, Security and Dependability in a New Era

Ch28-I044963.fm Page 134 Thursday, July 27, 2006 7:12 AM
Ch28-I044963.fm
134
134 Page 134 Thursday, July 27, 2006 7:12 AM
transported to a second process factory for material recycling, component reuse or landfill. On the
other hand, if a product is disassembled and its condition is checked at the user's site or the nearest
factoiy, and each component is then transported directly to the second process factory, the
transportation cost and lead-time will be reduced.
Material Component
Component
manufacturing
recycling manufacturing
Material flow in existing
Component Product Material flow in existing
Product
Disassembling
Disassembling
reusing assembling W' concentrated disassembly
assembling
concentrated disassembly
system
system
Material flow
_ _ ^ Material flow in ubiquitous
ubiquitous
in
Thermal recycling and disassembly system
disassembly system
and
recycling
Thermal
- • I
Landfilling
User
User 1 Landfilling
Figure 1 Differences between material flows of the concentrated and ubiquitous disassembly systems
INFORMATION SYSTEM ARCHITECTURE FOR THE UBIQUITOUS DISASSEMBLY
SYSTEM
Logistics planning to minimize transportation costs and lead-time seems to be solvable with an
conventional planning method, but it is not so simple. The product recovery process contains many
uncertainties, such as what, when and where products will be returned.
• What will be returned?
There are sometimes unknown components in a returned product because users have customized it. A
product identification method is required and, if possible, information about the use conditions of the
product should be recorded.
• When will products be returned?
We cannot estimate accurately the amount of returned products. However, the reuse plan should be
decided upon before the product is returned. Sometimes the reuse plan will change after a product is
returned. Rapid matching of demand and supply is needed.
• Where will products be returned?
We cannot predict where a returned product will appear because the users are distributed worldwide.
Even if there is only a small-scale factory near the returned product, the recovery process should be
started there.
To cope with the uncertainties of the product recovery process, three functional requirements are
arranged for the ubiquitous disassembly system. Each of the following requirements corresponds to the
relevant uncertainty condition written above.
• Sharing information on target products throughout all life cycle stages
All products should have a unique ID number, and their life-cycle information, which includes
historical records of their use conditions and assembly structure, should be recorded and managed for
each component individually throughout its life. In this paper, RFID will be introduced as a realization
method.
• Rapid matching of demand and supply for recovered components and materials
The demand and supply for reusable components are adjusted. Tn this work, this function is realized as
a blackboard system among product agents.
• Operation with inexpensive and flexible equipment
The disassembly operations are assigned to appropriate workers and/or robots for the situation. In this
work, this function is realized as a blackboard system among operation agents.