| Theory of Constraints is based on the premise that the rate of goal achievement is limited by at least one constraining process. Only by increasing flow at the bottleneck process can overall throughput be increased. |
|
So far as manufacturing operations management is concerned,
the solution is to 'pull' materials through the
system, rather than push them into the system. The primary methodology applied by
Optiflow-Le to manage constraints is the
Drum-Buffer-Rope (DBR). Drum-Buffer-Rope is a manufacturing execution methodology, named for its three components.
|
| Drum represents finite capacity of the plant including human resources. |
| Buffer protects the Drum. Buffers in
DBR have time as their unit of measure, rather than quantity of material. Buffers make sure that the successor process has enough material to keep producing when exceptions occur in predecessor processes. |
| Rope is the work release mechanism for the plant. If jobs are pulled ‘before time’, it results in high work-in-progress which in turn slows down the entire system. Requires that jobs be
sequenced in such a way that it is released 'Just-in-Time'. |
| Initially,
our scheduling & sequencing system will provide a
smooth, tightly coupled schedule. While the work is in progress, exceptions occur. From this point onwards, it is driven by exceptions such as
disruptions in supply of raw-materials, equipment break-down, non-availability of human skills, defective material ... and so on. While most of these exceptions can be automatically handled by re-scheduling, Optiflow-Le provides for five constraint handlers. |
| Production Rate Constraint
: Used to fix the daily / shift production rate. Simplest way to make sure that the deliveries are met. Fix the daily production
rate and the rest is managed automatically to provide you with the best possible execution
sequence. |
| Cooling
/ Change-Over Time Constraint : Used to enforce gaps between predecessor and successor operations. Increase the cooling time to increase kanban
buffer. Reduce the cooling time to attain a smooth workflow.
|
| Kanban Loop Constraint
: Kanban Loops are enforced as a constraint in Optiflow-Le. By manipulating kanban loop quantity, you can exercise control over the entire flow. Please refer overview of Kanban Techniques to learn more. |
| Operational Constraint
: Used to assign a particular operation to a particular shift and to extend time beyond the specified boundary. For ex., if an operation (assigned to a shift) takes 10 hours to produce one unit and shift timings are for 8 hours, you can extend the shift timing for this particular operation by 2 hours.
|
| Inventory Constraint
: Used to synchronize availability of
raw-material with operations. Specify/import the date and time at which raw materials / components / parts
are expected to be in-house and re-schedule. This could either be expressed as a constraint or be updated in the BOM module. |
| By applying a combination of these constraints, you can handle most exceptions with ease.
Please
contact support@optiflow-le.com
for further clarifications & assistance. |
