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11 Production Tools / Optimization User Manual Line Computer UNIX 11.4 Optimization Dial og Software Version 501.xx 01/99 Issue 11 - 28 11.4.3.2 Examples of Parameter Settings The parame ter settings for Set -Up Opti miz…
User Manual Line Computer UNIX 11 Production Tools / Optimization
Software Version 501.xx 01/99 Issue 11.4 Optimization Dialog
11 - 27
- DETERMINATION OF RUN TIME:
Optimization run time increases exponentially with the number of jobs. The quality of the setup can be set
via the run time: long run time -> good setup, short run time -> poor setup. The run time of Optimization
can be limited. Once the preset run time is exceeded, or the preset number of iteration steps completed,
Optimization is aborted. The best solution hitherto found continues to be used.
Optimization can produce reproducible (parameter: no. of iteration steps) and non-reproducible results
(parameter: Board Booster: Program run time per lot).
- Board Booster: Program run time per lot [sec]
This parameter allows you to define how long Optimization is to run for a given job. By multiplication
with the number of jobs contained in a lot file it is possible to determine the total run time of Optimiza-
tion for that lot file. A more optimized setup is computed requiring, however, more computing time. The
optimization results are not reproducible.
- No. of iteration steps
This parameter allows you to define how many Optimization runs (iteration steps) are to be performed
until a setup is established. Thereafter, Optimization is aborted and the best setup selected. The opti-
mization results are reproducible, however the time required for optimization cannot be precisely pre-
determined.
Meaning of the buttons
- Reset
This button is used to reset the standard values to the default values. They are deleted when so doing.
- OK
This button is used to accept the modified values.
- Cancel
This button is used to discard the modified values and to restore the previous state.
11 Production Tools / Optimization User Manual Line Computer UNIX
11.4 Optimization Dialog Software Version 501.xx 01/99 Issue
11 - 28
11.4.3.2 Examples of Parameter Settings
The parameter settings for Set-Up Optimization greatly depend on the frequency of setup changeover
operations taking place during a production run.
Three examples have been selected to show how the parameters can be set in different production situations:
● highly flexible production: many different jobs are processed in a very short time with the setup
changeover operations required.
● flexible production: frequent setup changeover operations are carried out whereby identical jobs are
also processed over and over.
● inflexible production: only one single setup is used for production over a long period of time.
Example 1: Highly flexible production
Setup problem:
In the case of a highly flexible production, setup changeover operations are performed daily in order to
produce new products. Setup changeover is carried out job-specifically.
Objective:
A setup is to be calculated for a given job as fast as possible. As little time as possible is to be expended
on the setup changeover. Production time plays is of minor importance.
Parameter settings:
● Clustering according to the Sequence method.
● Maximum number (feeders) if dominant: 1.
● No. of iteration steps: 1
(With a setting of 0 one single setup is created. It is, however, not optimized. This is the fastest
method for obtaining a setup.).
Lot file setting:
● Set the lot size to 1 so that only the setup changeover time is of importance.
● Enter an initial setup, i.e. the current setup of the line.
User Manual Line Computer UNIX 11 Production Tools / Optimization
Software Version 501.xx 01/99 Issue 11.4 Optimization Dialog
11 - 29
Effect:
From the initial setup a follow-up setup is computed in the shortest possible amount of time, having the
following features:
● A minimum changeover time from the initial setup to the follow-up setup is achieved.
● Every component is set up only once. The dominance of components is suppressed.
● Feeders with two compartments that are taken over from the initial setup and integrated into the
follow-up setup remain set up on the exactly same tracks as before.
● Components of the initial setup that are not required remain at their location.
Example 2: Flexible production
Setup problem:
In the case of flexible production, frequent setup changeover operations are performed with identical jobs
also being produced over and over again. Planning is medium-term.
Objective:
Grouping of products into setup families with the focus on short production times. Setup changeover
operations should be limited to changeover tables as far as possible.
Parameter settings:
● Clustering according to the Mean value method.
● Maximum number (feeders) if dominant: 2.
● Number of iteration steps: 5.
Lot file setting:
● The lot size is to be set to a realistic value.
● Enter a fixed setup, if desired.
Effect:
In a medium amount of time a setup or a setup family is calculated having the following features:
● Changeover time is taken into account depending on the lot size.
● Changeover operations are limited to the changeover trolleys (where configured).
● Production time is optimized. A compromise between production time and changeover time is
reached.