SlabFlow Invoicing Engine

1. Executive summary

SlabFlow’s invoicing engine is built for stone distributors and fabrication shops that sell full slabs, cut pieces, and fabrication services (cutting, edging).

Unlike generic billing software, SlabFlow connects each invoice line to real slab inventory, reserves stock on draft, updates stock on confirm, and automatically creates remnant slabs after cuts.

flowchart LR subgraph Problems P1[Excel errors] P2[Double-sold slabs] P3[Wrong sq.ft] P4[Lost remnants] P5[No cut planning] end subgraph SlabFlow S1[Linked inventory] S2[Draft reserve] S3[Measurement engine] S4[Auto remnant] S5[Order planner] end P1 --> S1 P2 --> S2 P3 --> S3 P4 --> S4 P5 --> S5

2. Scenario walkthrough (live screens)

The following screenshots are from the actual SlabFlow tenant application. Each scenario matches a common counter workflow.

Scenario 1

New invoice — 3-step counter flow

Staff selects customer, then adds items. Each item follows: type → stock → billing.

Open Invoices → New Invoice
Select customer from dropdown
Add line items (full slab or cut pieces)
Save draft or confirm sale

New invoice screen with customer selection and Item 1 full slab / cut pieces choice

Scenario 2

Full slab sale — customer buys whole slab(s)

Example: Builder wants 3 identical 8'×4' Carrara slabs as-is.

Choose Full Slab
Search by material, size, or slab code (not a full yard list)
Select slab(s) → bill = full area × full slab rate per slab

Full slab sale type selected with slab search filters

Slab search results after filtering by material

Scenario 3

Cut pieces order — size + quantity fulfillment

Example: Customer needs 10 pieces of 4'×4' from a material — system finds which slabs can fulfill the order.

Choose Cut Pieces
Enter material, piece size, total quantity
Click Find slabs for this order
Review allocation + cut layout → Apply to invoice

Cut pieces order planner with material size and quantity

Order planner results showing slab allocation and cut layout matrix

Scenario 4

Invoice list & confirmed sale detail

Track draft vs confirmed invoices, view line totals, record payments.

Confirmed invoice detail with line items and payment section

Scenario 5

Inventory after cuts — remnants in stock

After confirm, usable leftovers become AVAILABLE remnants (with profile: RECT / L-shape).

Inventory list showing slab status and remnant profiles

3. Problems we solve

Industry pain	SlabFlow solution
Which slab did we sell?	Each line links to specific slab IDs
Two customers quoted same slab	Draft reserves slabs
Full slab vs cut pricing	Separate full slab & cut piece rates
10× 4'×4' order	Order planner + cut layout
Lost remnants	Auto inventory on confirm
Feet + inches	Native 7'-6" × 2'-0" format
GST / payments	Tax on subtotal + receipt recording

4. Invoice lifecycle

stateDiagram-v2 [*] --> DRAFT: Create DRAFT --> DRAFT: Edit DRAFT --> CONFIRMED: Confirm sale DRAFT --> CANCELLED: Cancel CONFIRMED --> [*]: Paid CANCELLED --> [*]: Released

Status	Inventory	Accounting
DRAFT	Slabs → RESERVED	Not final
CONFIRMED	SOLD / cut + remnant	Journal entry
CANCELLED	Slabs → AVAILABLE	No sale

flowchart TD A[Customer] --> B{Item type?} B -->|Full Slab| C[Pick slab(s)] B -->|Cut Pieces| D[Order planner] C --> E[Billing] D --> E E --> F[Draft or Confirm]

5. Billing formula

Line Total = Material + Cutting + Edge

Component	Formula
Material	Billable sq.ft × rate (min billing may apply)
Cutting	Fabrication sq.ft × cutting rate
Edge	Edge RFT × profile rate

Material sq.ft by sale type

Sale type	Material sq.ft
Full slab (1)	1 × slab area
Full slab (N)	N × slab area
Cut order (total Q)	Q × piece area

6. Inventory & remnants

flowchart TD A[Parent slab] --> B[Cut on invoice] B --> C{Leftover ≥ min?} C -->|Yes| D[Remnant in stock] C -->|No| E[Mark SOLD waste] D --> F[Profile: RECT / L_SHAPE]

Profile	Meaning
RECT	Single rectangular remnant
L_SHAPE	Two usable strips after corner cut
MULTI	More than two regions

┌─────────────────────────────┐
│ ■ ■ ■ │   Usable remnant    │
│ ■ ■ ■ │      (amber)        │
│───────│                     │
│ waste │                     │
└─────────────────────────────┘
  Green ■ = pieces sold

7. Included vs planned

Included today

Full slab & cut piece billing
Order planner + cut layout visualization
Remnant auto-inventory with profile
Edge profiles & cutting charges
GST, draft/confirm/cancel, payments

Planned (Phase 2)

Feature	Notes
Sink cutout charges	Per-hole pricing (undermount, top mount)
Cooktop / tap holes	Fabrication add-on line items
CNC complex shapes	Non-rectangular nesting

8. Validation checklist

Please mark Yes / No / Notes for your operation:

#	Question	Your answer
1	Sell full slabs at full-slab rate per sq.ft?
2	Sell cut pieces at a different (higher) rate?
3	Customers order by piece size + quantity?
4	Need to reserve material while customer decides?
5	Remnants re-sold and tracked in stock?
6	Feet + inches is standard format?
7	Charge edging separately (RFT × profile)?
8	Charge cutting per sq.ft fabrication?
9	Need sink / hole charges as separate items?
10	GST applied on invoice subtotal?

9. Glossary

Term	Definition
Slab	Single stone unit with unique code
Remnant	Leftover after cut, new inventory item
Draft	Unconfirmed invoice; slabs reserved
Order planner	Fulfill size + qty from available stock
Cut layout	Visual map of pieces, remnant, waste