Optimization logic option


Optimization logic option is a feature for creating more ideal schedules by rearranging the sequence of operations assigned to a schedule. You can achieve various targets such as setup time minimization and juxtaposing operations of same item depending on how you specify the scheduling parameter.


Commands for Optimization Logic

The sequence control command requires the optimization logic option.


Sequence Control Command

Creates an optimized schedule while rearranging the sequence of operations assigned to the same resource based on the scheduling parameter settings. Rearranging will be performed after analyzing the status of the schedule immediately before rearranging. Operations will not be moved to other resources. Therefore, the result of rearrangement will be affected by how the operations were assigned the last time.
You can also specify the range for which to rearrange the sequence of operations. For example, you can control to avoid an operation assigned to a month ahead from moving to the time soon after the current time even when there is another operation around that time in which the same item is produced.

You will use the following properties in the Optimization tab of the scheduling parameter settings for the sequence control command.

Sequence control evaluation rules

Specify here any name and a sequence control evaluation rule will be added with that name. If you click on the arrow mark shown to the left of the specified name, the properties window will be switched to display properties for a sequence control evaluation rule.

Order start buffer

When there is any potential load such as changeover that is not known before assigning operations, you can use this property to consider leeway time in scheduling. When no value is specified, the leeway time will be automatically calculated in Asprova.
The automated calculation detects the day where the load is highest. This applies to the state just before the treatment is undertaken as well as to the period between targeted resource's assignment start time and its assignment end time (if both assignment start time and assignment end time are set up for the planning parameter, this will be applied.) The exceeding portions will be then calculated in terms of days.
Examples:
*
In case the load ratio is 300% on the day when the load is highest, the number of excess days is 3.
* In case the load ratio is 120% on the day when the load is highest, the number of excess days is 2.
*
When no days exceed 100%, it will be one day.
This is also the range where the time axis rearranges the order.

Sequence control evaluation rules

Specify how you want to arrange the sequence of operations. You can specify different rules for each resource.

Target resources

Specify here resources for which to apply this sequence control evaluation rule.
You can specify multiple resource and resource groups. If this property is blank, the rule will be applied to resources for which no other sequence control evaluation rules are specified.

Sequence control evaluation keys

Specify here any name and a sequence control evaluation key will be added with that name. If you click on the arrow mark shown to the left of the specified name, the properties window will be switched to display properties for a sequence control evaluation key.

Sequence control evaluation keys

Used as a basis for rearranging operations. The higher the keys are listed on the list, the higher the priority. The second key will not be used unless multiple operations get the highest evaluation score when they are evaluated using the first key.

Evaluation expression

An expression to specify what to evaluate. ME in the expression means a sequence control evaluation object. The followings are the main properties you can use for the expression.

 During evaluation - left operation (TentAssignLeftOper)Operation to the left
 During evaluation - right operation (TentAssignRightOper)Operation to the right
 During evaluation - target operation (TentAssignOperation)Target operation to evaluate
 During evaluation - setup time, During evaluation - production time, and During evaluation - teardown time (TentAssignSetup/Production/TeardownTime)Setup, production, and teardown times of the target operation to evaluate
 During evaluation - setup start time, During evaluation - production start time, and During evaluation - teardown start time (TentAssignSetup/Production/TeardownStartTime)Setup, production, and teardown start times of the target operation to evaluate
 During evaluation - setup end time, During evaluation - production end time, and During evaluation - teardown end time (TentAssignSetup/Production/TeardownEndTime)Setup, production, and teardown end times of the target operation to evaluate
 During evaluation - target resource (TentAssignResource)Resource to evaluate
 During evaluation - wait time (TentAssignWaitingTime)Time period from EST to start time of the target operation
 During evaluation - idle time (TentAssignIdleTime)Idle time until the target operation starts on the target resource
 During evaluation - lateness penalty (TentAssignLatenessPenalty)Penalty when lateness occurs

Evaluation expression sub key

A property to specify how the results of the evaluation expression are evaluated.

 BiggerPrioritizes bigger values among the expression results.
 SmallerPrioritizes smaller values among the expression results.
 TruePrioritizes when the expression results are TRUE.
 FalsePrioritizes when the expression results are FALSE..
 AscendingArranges the expression results in ascending sequence.
 DescendingArranges the expression results in descending sequence.
 Ascending/DescendingArranges the expression results alternately in ascending and descending sequence.

When using a string-type evaluation expression for the sequence control evaluation key, only descending and ascending orders can be used as sub keys. For example, neither ascending nor descending order will be valid for order code and spec.

For the ascending order, descending order and up-and-down order of sub keys, the order will be changed in such a way that the evaluation either gradually rises or gradually falls.
For example, with ascending the result is like 1, 1, 2, 2, 3, 3
and with descending the result is like 3, 3, 2, 2, 1, 1
For ascending/descending, the result would be like 1, 2, 3, 3, 2, 1


Evaluation expression threshold

A basis to determine the limit of difference above which two evaluation results are regarded to be different.


Examples of sequence control evaluation keys

Example 1: Juxtaposing operations of the same item

NoPropertyContents
1Evaluation expressionME.TentAssignOperation.OperationOutMainItem == ME.TentAssignLeftOper. OperationOutMainItem
 Evaluation expression sub keyTrue

Example 2: Processing operations based on spec 5 so that operations with the same spec 5 value will not be processed consecutively as much as possible.

NoPropertyContents
1Evaluation expressionGetApplicableSpec(5, ME.TentAssignOperation) != GetApplicableSpec(5, ME.TentAssignLeftOper)
 Evaluation expression sub keyTrue

Example 3: Arranging operations in ascending num spec 1 value.

NoPropertyContents
1Evaluation expressionAbs( GetApplicableNumSpec(1, ME.TentAssignOperation) - GetApplicableNumSpec(1, ME.TentAssignLeftOper))
 Evaluation expression sub keySmaller

Example 4: Realizing setup minimization by rearranging the sequence of operations when the difference of due dates are within 2 days.

NoPropertyContents
1Evaluation expressionME.TentAssignOperation.Order.LET
 Evaluation expression sub keySmaller
 Evaluation expression threshold2d
2Evaluation expressionME. TentAssignSetupTime
 Evaluation expression sub keySmaller

Combinations of Commands

The sequence control command is used in combination with existing parameters and/or with "resource wise load leveling" and "time wise load leveling" commands.


Examples of command combinations

1. When there are multiple resource candidates for a process for which you want to rearrange the sequence of operations and the selection of the resources will affect the quality of the result of scheduling..

 1Resource wise load levelingExecutes resource wise load leveling.
 2Time wise load levelingExecutes time wise load leveling and calculates LST of each operation (when orders are assigned backward).
 3Sequence controlExecutes the sequence control command and rearranges the operations in an optimal sequence.

2. When there are few resource candidates for a process for which you want to rearrange the sequence of operations or the selection of the resources will not really affect the result of scheduling.

 1Time wise load levelingExecutes time wise load leveling and calculates the LST of each operation when loads are leveled among resources to which the operations are assigned.
 2Sequence controlExecutes the sequence control command and rearranges the operations in an optimal sequence.

3. When you want to rearrange operations assigned using the existing scheduling parameter to create a better schedule

 1Existing scheduling parameterCreates a schedule using the scheduling parameter that is usually used. (Since the load leveling process is not included, you will need to specify enough times in the properties "Order start buffer" and "Order end buffer".)
 2Sequence controlBased on the result of scheduling in the above 1, rearranges the operations in an optimal sequence.

Scheduling parameter settings

The following scheduling parameter settings (General, Settings tabs) will be ignored by the sequence control command:

- Enable inventory constraints

- Assignment type

- Temporary operation fix

- Dispatching rule

- Resource evaluation

- Resource selection method

- Passed assignment start time

- Passed assignment end time

- Passed EST

- Passed due date

- Max # resource candidate

- Auto-generate master instructions

- Assignment failed (time contraints MAX)

- Assignment failed (resource lock)


The “Dispatching rule absolute” property works from Ver. 14.1.1.70.
In sequence control, basically, operations can be arranged from the past to the future, but depending on the changeover settings, there are operations that cannot be so arranged.
For example, in the following example, the setting is for the sequence 1, 2, 3, 4 in “Sequence control evaluation key” of the “Sequence control evaluation rule” scheduling parameter, but assignment is done in the sequence of 1, 4, 2 and 3.

 

This is due to the fact that, while the state below results when 1, 2 and 3 are assigned, when the last number, 4, is assigned, assignment between 1 and 2 becomes impossible due to the changeover setting.

 

Even in such a case, if you want to assign 4 after 3, the following assignment is possible if "Dispatching rule absolute” is set to “Yes”.

 


Notes

1. Optimization logic option is an optional feature and a separate license is required in order to use it.

2. Since forward scheduling is basically used for sequence control, lateness may occur even for backward orders. In that case, please try increasing buffer time.

3. When you also use the event option, please execute the event Optional Features after sequence optimization. Also, if the event optional feature is expected to cause a difference in the scheduling result, please specify a longer buffer time in advance.

4. The sequence control command processes only operations of manufacturing orders. When you need to adjust purchase orders and sales orders according to the result of sequence optimization, please compile another scheduling parameter to do the adjustment.

5. Sequence control will not perform split operations. The operations that have already been split will be swapping places while remaining split, but any changes in the split specifications will not be reflected.

6. When an operation uses multiple resources, and if the sequence settings apply to multiple resources, they will only apply to one resource. If multiple resources contain main and sub resources, they will apply to the main resource. If there are sub resources only, it remains uncertain as to which sub resource will be applicable.

7. Sequence control will not swap places for the following kinds of operation. If they are assigned to the Gantt chart, they will remain as they are. (However, the assigned operations will impact the evaluation results of sequence control.)

- Time-fixed operations whose assignment time is determined and operations assigned by the result operations will not be processed.

- Operation for which orders are not subject to assignment


HelpNo.:777500
© Since 2019 Asprova Corporation, All rights reserved.