Overview
The nominal grid is a powerful filtering system that automatically assigns appropriate nominal codes to invoices during the posting process. This system uses a hierarchical approach where invoices "fall through" the grid from top to bottom until they find a matching line that satisfies all defined criteria.
What Are Nominal Grid Filters?
Nominal grid filters are conditional parameters applied to individual lines within the nominal grid. These filters act as gatekeepers, determining whether an incoming invoice matches the specific criteria required to use that line's associated nominal code.
Key Characteristics
Multi-criteria matching: An invoice must satisfy ALL filters on a line to be assigned that line's nominal code
Top-down processing: Invoices are evaluated against grid lines sequentially from top to bottom
First-match assignment: The invoice stops at the first line where all filters are satisfied
Automatic categorization: Reduces manual intervention in the invoice posting process
How Filters Are Displayed
Visual Organization
Filters are organized and displayed using a visual grouping system that makes them easy to identify and manage:
Filter Bubbles: Each filter type is contained within a distinctive grey "bubble" that groups related filters together. This visual separation helps users quickly understand the different types of criteria applied to each line.
Hover Information: When you position your mouse cursor over any filter bubble, a tooltip appears showing the specific filter type (such as Product, Account, Outlet, etc.), providing instant clarity about what each filter represents.
In the below example is a line with the following filters:
Product Filter: "SK8" (8-yard skip)
Waste Type Filters: "MIXED-GEN" and "BRICKS"
These appear as separate grey bubbles:
One bubble containing "SK8" (Product type)
Another bubble containing "MIXED-GEN, BRICKS" (Waste Type)
This separation occurs because Product and Waste Type are different filter categories, even though they apply to the same grid line.
Filter Processing Logic
The "Waterfall" Effect
When an invoice is posted to the system, it follows a predictable path through the nominal grid:
Starting Point: The invoice begins evaluation at the topmost line of the grid
Sequential Evaluation: Each line is checked in order from top to bottom
Criteria Matching: For each line, the system compares the invoice data against ALL filters on that line
Decision Point: If all filters match, the invoice "stops" and adopts that line's nominal code
Continuation: If any filter doesn't match, the invoice continues to the next line down
Practical Example: Skip Hire Invoice Processing
Let's trace through a real-world example to illustrate how the system works:
Invoice Details
Service: 8-yard skip hire
Product Code: SK8
Waste Type: MIXED-GARD (Garden Waste)
Grid Evaluation Process
Line 1 Evaluation:
Product Filter: SK8 ✓ (matches)
Waste Type Filter: MIXED-GEN OR BRICKS ✗ (doesn't match MIXED-GARD)
Result: Continue to next line
Line 2 Evaluation:
Product Filter: SK8 ✓ (matches)
Waste Type Filter: [Different waste types] ✗ (doesn't match MIXED-GARD)
Result: Continue to next line
Line 3 Evaluation:
Product Filter: SK8 ✓ (matches)
Waste Type Filter: MIXED-GARD ✓ (matches)
Result: All criteria satisfied - assign this line's nominal code
Best Practices for Grid Organization
Strategic Line Ordering
Since invoices process from top to bottom, the order of your grid lines significantly impacts system performance and accuracy:
Most Specific First: Place lines with the most detailed and restrictive filter combinations at the top of the grid. These lines should target very specific invoice types that require precise categorization.
Gradual Broadening: Arrange subsequent lines in order of decreasing specificity, with each level catching invoices that didn't match the more restrictive criteria above.
Catch-All Bottom: Consider placing broad or default lines toward the bottom to handle edge cases or general categories.
Filter Design Guidelines
Comprehensive Coverage: Ensure your filter combinations cover all possible invoice scenarios that might occur in your business operations.
Avoid Conflicts: Design your filter logic to prevent situations where similar invoices might match multiple lines unintentionally.
Regular Review: Periodically audit your grid structure to ensure it still aligns with your current business processes and product offerings.
Maintenance and Optimization
Regular Auditing
Establish a routine for reviewing your nominal grid performance:
Monthly Review: Check for invoices that required manual intervention
Filter Utilization: Identify lines that are never or rarely used
Processing Efficiency: Monitor how many lines invoices typically pass through before matching
Performance Optimization
Consolidate Similar Lines: Combine lines with nearly identical filter patterns
Optimize Filter Order: Move frequently-matched lines higher in the grid
Remove Redundant Filters: Eliminate filters that don't meaningfully differentiate between invoice types