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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 - 26 - Filling up changeove r tables This param eter per mits y ou to spe cify tha t on t…
User Manual Line Computer UNIX 11 Production Tools / Optimization
Software Version 501.xx 01/99 Issue 11.4 Optimization Dialog
11 - 25
- Mean value:
Starting situation: A number of jobs exist that are to be produced over and over again at varying
and unforeseeable instances.
Optimization: Optimization forms setup clusters resulting in minimum changeover times for any
setup changeover procedure desired.
- SETUP CHANGEOVER TIMES
Set-Up Optimization requires a basis for the calculation of the changeover times. The parameters listed in
the following can be set to specify how much time is required for setup changeover operations.
- Basic time for set-up changeover [sec]: The basic time refers to the time that elapses between the
last placement from the predecessor setup and the first placement of the follow-up setup. The actual
setup changeover times are not included in the calculation. The default setting is 600 sec.
- Trolley changeover time [sec]: Estimated time required for the removal and installation of a compo-
nent changeover table. While the placement process continues, the feeders are prepared, away from
the line, on a second changeover table. The changeover table is then exchanged completely during the
changeover procedure. The default setting is 180 sec (= 90 sec for taking down + 90 sec for setting up).
To be able to use this parameter, a feeder part must be defined as component changeover table in the
Configuration Editor (see chapt. 12).
- Feeder changeover time [sec]: Estimated time required for the removal and installation of a feeder
on a fixed component table. The feeders are prepared outside the line with the placement process
continuing. They must be changed over individually; this is why the time required for the setup
changeover increases with the number of machine components to be changed over. The default set-
ting is 60 sec (= 30 sec for taking down + 30 sec for setting up).
- COMPONENT TYPE
The following parameters can be set for the component supply units. They will affect - with one exception -
the entire setup optimization.
- WPC refilled 100%
In a setup, not all levels of the Wafflepack Changer need necessarily to be occupied by
components.
This parameter permits you to specify that Optimization is to assign components to all empty trays as
well, i.e. in accordance with their usage frequency rate across all PCBs of a lot file.
- Using the nozzle changer configuration
This parameter permits you to specify that the current configuration of the respective nozzle changer
is to be used and not to be changed by Set-Up Optimization.
- Calculation of a common nozzle configuration per head
This parameter enables you to specify that Setup Optimization is to compute for all PCBs a nozzle
configuration per head and to save it to the setup file.
11 Production Tools / Optimization User Manual Line Computer UNIX
11.4 Optimization Dialog Software Version 501.xx 01/99 Issue
11 - 26
- Filling up changeover tables
This parameter permits you to specify that on the changeover tables components from the initial setup
are to be included in the follow-up setup, even if they are not required. The setup changeover effort
can thus be kept to a minimum.
Note: This parameter only affects Clustering.
- Fixed set-up components to be set up only once
This parameter is only relevant where a fixed setup is defined. It is possible to define whether or not a
component already contained in the fixed setup is allowed to be set up by Optimization at another or
several other locations that may be more advantageous.
- Allocate components to empty feeder compartments
Activation of this parameter causes empty compartments or feeders to be removed from the fixed
setup so that they are available for reallocation by the setup optimization. New feeders will only be set
up if required.
- Remove components that are not required from fixed set-up
This parameter is used to define that components that are not contained in the PCB types to be opti-
mized will be removed from the fixed setup and made available for reallocation by the setup optimiza-
tion. New components can only be added to the fixed setup if the button "Allocate components to empty
feeder compartments" is activated in addition (see above).
Dynamic changeover procedures are supported. If a setup family was formed by, let’s say, five pro-
ducts, such setup family can be used as a fixed setup for a new setup optimization run if two products
were removed and two new products were added. No changeover procedures need therefore be per-
formed for the three remaining products, and hence no tests have to be performed. This results in
considerable time savings. The two new products will be optimally integrated into the ’stripped down’
fixed setup thus allowing for a continuous dynamic setup optimization process.
- Maximum number if dominant
This parameter allows you to define the maximum number of times a dominant component type may
be set up. If only a minimum of setups is to be created, the number of feeders in the case of domi-
nance should be limited to 1. With the setting of 0, Set-Up Optimization can decide on its own how
often the component type at issue is to be set up.
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.