24 Life Cycle Simulation of Machine Parts with Part Agents
345
Profit, cost, and environmental load are selected as parameters to be generated
during each life cycle stage of the part. Part agents evaluate candidate next stages as
previously described by combining these three parameters.
Because an appropriate combination of these parameters may differ according to
evaluation aspects, the following two equations are provided as evaluation indices
of the life cycle stage.
The first is INDEX as follows:
INDEX = pr o f it−cost−environmental load
(24.3)
INDEX is an index that shows how much profit remains by subtracting the cost
and environmental load.
The second is the Total Performance Index(TPI) (Kondo et al. 2008) as follows.
T P I =
pr o f it
√
cost × environmental load
(24.4)
TPI is an index that shows how efficiently profit can be generated given the cost
and environmental load.
In these two equations, a, b and c are coefficients for weighting, respectively, for
each user, the part agent can evaluate the life cycle stage suitable for various users.
The part agents evaluate the most appropriate stage using these indices.
24.4 Reuse Method
There are several means by which consumers can reuse products, such as buying
and selling through the used market and buying and selling between neighboring
inhabitants. The reuse method the user desires depends on individual preference and
the environment of the region where the user lives.
Three types of reuse methods were provided in this study to carry out the simulation corresponding to the user’s manner of thinking and the surrounding environment
as follows: (1) reuse through the market, (2) reuse via trade between users, (3) reuse
combining these two means. Each is described in detail in the following.
24.4.1 Reuse Through the Market
Some users may have resistance against transactions between users. Therefore, reuse
through the market is provided as one of the reuse methods.
The functions of the market for used parts are storage, cleaning, repairing, selling
and buying.
345
Profit, cost, and environmental load are selected as parameters to be generated
during each life cycle stage of the part. Part agents evaluate candidate next stages as
previously described by combining these three parameters.
Because an appropriate combination of these parameters may differ according to
evaluation aspects, the following two equations are provided as evaluation indices
of the life cycle stage.
The first is INDEX as follows:
INDEX = pr o f it−cost−environmental load
(24.3)
INDEX is an index that shows how much profit remains by subtracting the cost
and environmental load.
The second is the Total Performance Index(TPI) (Kondo et al. 2008) as follows.
T P I =
pr o f it
√
cost × environmental load
(24.4)
TPI is an index that shows how efficiently profit can be generated given the cost
and environmental load.
In these two equations, a, b and c are coefficients for weighting, respectively, for
each user, the part agent can evaluate the life cycle stage suitable for various users.
The part agents evaluate the most appropriate stage using these indices.
24.4 Reuse Method
There are several means by which consumers can reuse products, such as buying
and selling through the used market and buying and selling between neighboring
inhabitants. The reuse method the user desires depends on individual preference and
the environment of the region where the user lives.
Three types of reuse methods were provided in this study to carry out the simulation corresponding to the user’s manner of thinking and the surrounding environment
as follows: (1) reuse through the market, (2) reuse via trade between users, (3) reuse
combining these two means. Each is described in detail in the following.
24.4.1 Reuse Through the Market
Some users may have resistance against transactions between users. Therefore, reuse
through the market is provided as one of the reuse methods.
The functions of the market for used parts are storage, cleaning, repairing, selling
and buying.