Configuring MRP Parameters and Planning Horizons
Access MRP parameters through Production > Planning > MRP Parameters (SLMrpParms). Set the Planning Horizon to define how far into the future MRP calculates requirements, typically 12-26 weeks for manufactured items and 8-16 weeks for purchased items. Configure the Planning Fence to distinguish between the firm zone (no automatic changes) and the planning zone (MRP can suggest new orders).
The mrpparms table stores these global settings. Set the Demand Source flags to include customer orders, forecasts, safety stock requirements, and inter-site transfer demands. Configure the Planning Time Fence in days to prevent MRP from modifying orders within your frozen manufacturing schedule, typically set to the cumulative manufacturing lead time of 2-4 weeks.
- Set Planning Horizon in MRP Parameters to 12-26 weeks for manufactured items coverage
- Configure Planning Time Fence to freeze the near-term schedule from MRP modifications
- Enable demand sources: customer orders, forecasts, safety stock, and inter-site transfers
- Set lot sizing rules per item: lot-for-lot, fixed quantity, EOQ, or period-of-supply
Executing MRP Regeneration and Processing Options
Launch MRP regeneration from Production > Planning > Generate MRP (SLGenMRP). Select Regeneration mode to rebuild all planning data from scratch, as opposed to Net Change which only processes modified items. Choose the item range, warehouse scope, and planner code filters to focus the run if needed.
The MrpRegenSp stored procedure processes items in low-level-code sequence, starting with finished goods (level 0) and working down through sub-assemblies and raw materials. A full regeneration for a mid-size manufacturer with 5,000-10,000 active items typically runs in 15-45 minutes. Schedule MRP regeneration as a nightly batch job through SyteLine's Batch Processing utility to ensure planners have fresh data each morning.
Run net change MRP during the day for urgent replanning needs.
- Select Regeneration mode in Generate MRP to rebuild all planning data completely
- Filter by item range, warehouse, or planner code for focused partial regeneration runs
- Schedule nightly batch MRP regeneration through Admin > Batch Processing utility
- Run Net Change MRP during business hours for urgent demand or supply change replanning
Analyzing MRP Results and Exception Messages
After MRP completes, review results on the MRP Exception Messages form (SLMrpExceptions). Exception messages fall into categories: Action messages recommend creating, rescheduling, or canceling orders. Review planned purchase orders on the Planned Purchase Orders form and planned production orders on the Planned Orders form.
The mrp_exception table stores all generated messages with action codes, item references, and suggested dates. Use the MRP Pegging inquiry (SLMrpPegging) to trace demand sources for any planned order back to the originating customer order, forecast, or safety stock requirement. Prioritize exception messages by filtering for items with A-class ABC classification and critical path impact.
Most planners process 50-100 exception messages daily in a well-tuned MRP environment.
- Review MRP Exception Messages (SLMrpExceptions) filtered by action type and priority
- Use MRP Pegging inquiry to trace demand sources for any planned order back to origination
- Process planned purchase orders by firming and converting to actual POs in Purchasing
- Target processing 50-100 exception messages daily with A-class items taking priority
Try it here, free
SYSPRO MRP Checklist
A checklist of the master data, parameters and review steps that decide whether SYSPRO MRP output can be trusted.
Frequently asked questions
How often should I run MRP regeneration versus net change in SyteLine?
Best practice is to run full MRP regeneration nightly as a batch job and use net change MRP 1-3 times during business hours for urgent replanning. Full regeneration ensures data integrity by rebuilding all planning calculations from scratch, catching any data corruption or missed transactions. Net change processes only items affected by changes since the last run, completing in 2-5 minutes versus 15-45 minutes for full regeneration. Approximately 80% of SyteLine manufacturers follow this nightly-regen-plus-daytime-net-change pattern.
Why does MRP generate too many exception messages in SyteLine?
Excessive MRP messages typically result from incorrect planning parameters. Common causes include lot sizing rules that fragment demand into many small orders (affects 30-40% of implementations), time fence settings that are too short allowing MRP to constantly reschedule near-term orders, and inaccurate lead times that trigger premature or late action messages. Review items generating more than 5 exception messages per week and adjust their lot sizing, lead time, and safety stock parameters. A well-tuned MRP system generates 50-100 actionable messages daily for a 5,000-item environment.
Can I run MRP for a single item or item group in SyteLine?
Yes, the Generate MRP form supports item range filtering that allows you to run MRP for a single item, a range of items, or items assigned to a specific planner code. Single-item MRP runs complete in under 30 seconds and are useful for urgent replanning after a demand spike or supply disruption. However, single-item runs may not capture cascading effects on sub-components. For comprehensive replanning of an item and all its components, use the low-level-code filter to include all items at and below the target item's BOM level.
Empower your planning team with Netray AI agents that analyze SyteLine MRP exception patterns, identify chronic rescheduling items, and recommend parameter adjustments to reduce planning noise by up to 40%.