Resource lock time option

Resource Lock


The resource lock time is used to lock a resource so that no operations will be assigned to that resource after an operation that is assigned to the resource ends. Here we will specify the resource lock time depending on the production time of the operation or its parent operation. Data scheme is as follows:

< Total Lock Time >< LockTimes >
| < DependableLockTime > ; < LockTimes >
| < DependableLockTime >
< DependableLockTime > < "PS" | "PE" >
("P" stands for "Parent", meaning the next process. "S" stands for "Start". "E" stands for "End".)
< LockTimes > < lockTime>
| < lockTime> ; < LockTimes >
< lockTime > < RelativeTime >
| < PercentValue > % < who >
| < production Value > # < who >
< who > "P" | "M"
("P" stands for "Parent", meaning the next process. "M" stands for "Myself", meaning the current process.)


Example

1. Locking a resource until parent operation's production start time.
PS
2. Locking a resource until parent operation's production end time and then another 120 minutes for cooling down the resource.
PE;120
3. Locking until 40% of the production time of the current operation + time that the resource assigned to the parent operation requires to produce 30 units + 500 minutes.
40%M;30#P;500

Notes about resource lock

To use a resource lock, you will need to check the property "Enable resource lock" in the Settings tab of the project settings and specify data in the property "Resource lock time" of a resource or a use instruction in IMT table (Ver.10 restricted feature). When resource lock is specified in both resource table and IMT table, the specified resource lock of use instruction in IMT table take precedence of the one in resource table.

Processes connected by a resource lock will be assigned at once when scheduling. At that time, operations connected by a resource lock will be considered when considering combinations of resource candidates. Therefore, the number of combinations of resource candidates tends to increase.

The more the number of combinations of resource candidates, the longer the scheduling process takes. If scheduling takes too much time because of using resource lock, you can shorten the scheduling time by specifying a small number for the property "Max # resource candidate". Click here for more information about resource candidates.

Also, since operations connected by a resource lock are assigned at once, dispatching orders of all the operations are the same. Therefore, the operations may be assigned in a different sequence from that of the dispatching rule of the scheduling parameter.


When the status of part of operations connected by a resource lock is "Completed", "Started", "Frozen", or "Released", or times of those operations are partly fixed, you can use

  • Assign result constrained operations command
  • Assign time fix constrained operations command

to assign operations connected by a resource lock and for which results are not specified. For example, if you do not use the Assign result constrained operations command and Assign time fix constrained operations command as in the setting below, operations connected by a resource lock and for which results are specified will be assigned in the first or second phase, and operations connected by a resource lock and for which results are not specified will be assigned in the third phase at the same time when operations not connected by a resource lock are assigned.

  1. Assign privileged operations
  2. Assign time fixed operations
  3. Assign/peg orders

If you insert the Assign result constrained operations command and Assign time fix constrained operations command as follows, operations connected by a resource lock and for which results are not specified will be assigned in the third or fourth phase before operations not connected by a resource lock are assigned. Thus, it is easy to satisfy the resource lock constraint.

  1. Assign privileged operations
  2. Assign time fixed operations
  3. Assign result constrained operations
  4. Assign time fix constrained operations
  5. Assign/peg orders

What to do when unable to follow resource lock constraint

When "Assign/pegged orders" command or "Assign manufacturing orders" command is assigned, you may choose how to deal with cases in which operations cannot be assigned in line with the resource lock constraint by specifying the property "Assignment failed (resource lock)" in the "Settings" tab of the scheduling parameter.

The following options are available for the property "Assignment failed (resource lock)":

Assign outside scheduling period

The operations bound by the resource lock constraint are all forcibly assigned outside the scheduling period.

Ignore constraint

The operations originally intended for assignment will be individually assigned by ignoring the resource lock constraint.

Assign to dummy resource

The constrained operations are all assigned to dummy resources.


Resource LockTask resource quantity

When assigning resource locks, the default quantity is one. However, this value can be modified by using Resource LockTask resource quantity property found in integrated master editor. This feature makes possible to lock several pallets or cases, for instance (From Ver.7.0.0).

Information about resource quantities of tasks can be found here.

In the example below, between the start of materials supply process and the end of moulding process special cases are used continuously. For this, a sub-process and resource lock are used. For Case 1 resource, the number of cases is set to 4, whereas task required resource quantity properties for items are set as follows:
H6 3 (requires three cases)
H7 2 (requires two cases)
H8 2 (requires two cases)

It looks like there is assignable time between the noons of 6/6 and 6/7, but because orders 10 and 6 both allocate two cases, no more orders can be assigned during this period. Further, as order 13 (and resource lock) takes three cases and there are no tasks that require only one case, simultaneous assignments with the order 13 do not exist.

 

Resource lock - disallow same resource

When multiple operations of which the next process is the same operation are assigned to a resource for which a resource lock dependent on the next process (such as PS and PE) is specified, the operations cannot satisfy the resource lock constraint if the resource does not have the resource quantity that is enough for assigning the multiple operations.

For example, in the following diagram, "PE" is specified for the property "Resource lock time" of resource R10. Since the resource quantity of resource R10 is set to 2, two operations can be assigned to the resource even when the resource lock is specified. However, if the resource quantity is 1, since the resource lock specified for each operation interferes the other operation from assigning to the locked time, the operations cannot be assigned sequentially.


In this case, you can use the property "Resource lock - disallow same resource" to specify whether multiple operations pegged to the same next process can be assigned to the same resource for which a resource lock dependent on the next process is specified.

When this property is set to "Yes", operations are not allowed to be assigned to the same resource. Therefore, you can omit combinations of multiple operations that cannot satisfy the resource lock from assignment to the resource. When you allow multiple operations that have the same parent operation to be assigned to the same resource, please set this property to "No".

 

Restrictions

- A resource lock is an optional feature and a separate license is required in order to use it.

- When there is a resource lock constraint between orders, you need to make a setting so that the pegging between the orders will not be changed because scheduling will be performed with the pegging status immediately before scheduling. If you use the "Assign/peg orders" command to assign operations, the pegging status may be changed after assigning operations. Therefore, please use the "Assign manufacturing orders" command instead.

- If you specify a resource lock that does not depend on the next process, you can concurrently use merge/branch processes and operation splitting without problems.

- If you specify a resource lock that does not depend on the next process, you can concurrently use merge/branch processes and operation splitting without problems.

1) When the "Resource lock time" is specified with "PS", the previous operation and the next operation are assigned to the same resource, the shortest time between the end time of previous operation and the start time of next operation (the start time of next operation's setup task in followed graph) will be the resource lock time. (After Ver.9.0.3.0)


2) Otherwise, the longest time between the end time of previous operation and the start time of next operation will be the resource lock time.

- If you specify a resource lock that depends on the next process and there are multiple processes in the next process, the next process for which the lock time will be the longest among other next processes will be locked. The behavior will be the same whether the multiple processes arise from process branching or static splitting.


- Negative values are not allowed when you specify "Absolute time" as lock time.

- For a resource lock that depends on the next process (e.g. PS), dynamic splitting will not be performed for connected processes.

- Dynamic operation splitting means to split operations according to the split settings in resources and master use instructions. On the other hand, static operation splitting means to split operations according to the split settings in items and operations.

- When the next process to serve as the basis of assignment for a resource lock task is unassigned, the resource lock task will remain assigned as it is and not be adjusted. When the next process is reassigned, the resource lock task will be adjusted.

- If the next process to serve as the basis of assignment for a resource lock task is assigned, and ultimately the assignment fails to cause forcible assignment, the resource lock task will not be adjusted.

- When scheduling backwards, operations may not be assigned correctly to the left. Please refer to confirmed behaviours Logic 28 for much more information.



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