Time Fences in Production and Supply Chain Planning

Time fences are boundaries that divide the planning horizon into different periods. They are used to control and manage the flow of materials and information in a production or supply chain planning system. By defining time fences, manufacturers can establish clear guidelines for when and how changes can be made to the production schedule. This helps to minimize disruptions and ensure that the production process runs smoothly.

Types of Time Fences

There are three main types of time fences used in production and supply chain planning:

1. Planning Time FenceThe planning time fence is a boundary within which the planning process does not alter the current material plan or master schedule. It restricts rescheduling in (creating earlier) order due dates or creating new planned orders for discrete items within the planning fence. However, it allows rescheduling out or canceling orders that create excess supply. For repetitive items, the planning process suggests rates of production within the planning time fence that differ from the current aggregate repetitive schedule by a defined acceptable rate increase or decrease.
2. Demand Time FenceThe demand time fence is a boundary within which the planning process only considers actual demand and does not consider forecast demand. Outside the demand time fence, the planning process considers forecast demand. It helps in distinguishing between actual and forecasted demand when calculating net demand requirements.
3. Release Time FenceThe release time fence is a boundary within which the planning process automatically releases planned orders to Oracle Work in Process as discrete jobs or to Oracle Purchasing as purchase requisitions. The planned orders must meet certain criteria, such as having a new due date within the release time fence and being for standard items (not for models, option classes, or planning items).

Benefits of Using Time Fences

Time fences offer several benefits in production and supply chain planning, including:

• Improved Planning AccuracyBy establishing clear boundaries for when and how changes can be made to the production schedule, time fences help to improve planning accuracy. This is because planners can focus on the most critical aspects of the schedule and avoid making unnecessary changes that could disrupt the production process.
• Reduced DisruptionsTime fences help to reduce disruptions to the production process by preventing last-minute changes to the schedule. This is because changes made within the time fence are more likely to be feasible and less likely to cause problems with other parts of the production process.
• Increased EfficiencyTime fences can help to increase efficiency in production and supply chain planning by allowing planners to focus on the most important tasks. By eliminating the need to constantly make changes to the schedule, planners can spend more time on strategic planning and analysis.

Conclusion

Time fences are a valuable tool for production and supply chain planning. By defining clear boundaries for when and how changes can be made to the production schedule, time fences help to improve planning accuracy, reduce disruptions, and increase efficiency.

References

• Overview of Time Fence Planning (MRP and Supply Chain Planning Help)
• Time Fence Control (MRP and Supply Chain Planning Help)
• Example 3 (AMGI Management)

FAQs

What are the different types of time fences used in production and supply chain planning?

The three main types of time fences used in production and supply chain planning are the planning time fence, the demand time fence, and the release time fence.

What is the purpose of a planning time fence?

The purpose of a planning time fence is to establish a boundary within which the planning process does not alter the current material plan or master schedule. This helps to prevent last-minute changes to the schedule and improve planning accuracy.

What is the purpose of a demand time fence?

The purpose of a demand time fence is to distinguish between actual and forecasted demand when calculating net demand requirements. Within the demand time fence, only actual demand is considered, while outside the demand time fence, both actual and forecasted demand are considered.

What is the purpose of a release time fence?

The purpose of a release time fence is to define a boundary within which the planning process automatically releases planned orders to production or purchasing. This helps to ensure that materials and components are ordered and produced in a timely manner to meet customer demand.

What are the benefits of using time fences in production and supply chain planning?

The benefits of using time fences in production and supply chain planning include improved planning accuracy, reduced disruptions, and increased efficiency.

How can time fences help to improve planning accuracy?

Time fences help to improve planning accuracy by establishing clear boundaries for when and how changes can be made to the production schedule. This allows planners to focus on the most critical aspects of the schedule and avoid making unnecessary changes that could disrupt the production process.

How can time fences help to reduce disruptions?

Time fences help to reduce disruptions by preventing last-minute changes to the production schedule. This is because changes made within the time fence are more likely to be feasible and less likely to cause problems with other parts of the production process.

How can time fences help to increase efficiency?

Time fences can help to increase efficiency by allowing planners to focus on the most important tasks. By eliminating the need to constantly make changes to the schedule, planners can spend more time on strategic planning and analysis.