Building a Multi-Level Assembly Routing in EDGEBIC

A multi-level assembly in EDGEBIC by User Solutions is modeled the way a real bill of materials works: the sub-assembly gets its own product and routing, and the parent references it as a material step, so the engine can build or net the component and then schedule the final assembly after it is ready. This walkthrough builds a two-level product (a sub-frame that feeds a finished cabinet) and schedules both. It is part of our worked examples series. The numbers here are illustrative, chosen to make the structure clear; the routing mechanics they demonstrate are the documented mechanics.

The Setup: A Cabinet Built From a Welded Sub-Frame

Lakeside Enclosures makes a control cabinet, CAB-100, whose core is a welded steel sub-frame, FRAME-S. The sub-frame is worth making as its own item: it is used across several cabinet models, and the shop likes to keep a few on the shelf. So the product structure is two levels:

• FRAME-S (sub-assembly): cut and weld, its own routing, sometimes stocked.
• CAB-100 (finished good): consume one FRAME-S, then mount, wire, and inspect.

Two products, two bills of routing, one reference linking them. That is a multi-level assembly.

Step 1: Build the Sub-Assembly's Own Routing

Dana, the planner, first sets up FRAME-S as a normal product. She creates a bill of routing for it and adds work center steps the ordinary way:

Each step names a real work center, so each consumes machine capacity and will appear as a bar on the Gantt. FRAME-S is now a fully schedulable product in its own right: you could raise a manufacturing order for it and run it exactly like any other job. That independence is the reason to model it separately rather than burying its two operations inside the cabinet routing.

Step 2: Build the Parent Routing With a Material Step

Now Dana creates the bill of routing for CAB-100. The finished cabinet's routing has one operation the others do not: it consumes a FRAME-S. She builds it in the BOR grid:

1. Material step for the sub-frame. She clicks Add Step, sets the sequence, and leaves the Work Center blank. She marks the step as a product (the Is Product flag), sets the Product to FRAME-S, and sets Quantity to 1 (one sub-frame per cabinet). She links its Next In Seq Id to the first assembly step. Because the work center is blank, the engine recognizes this as a material step: it consumes no machine time and gets an instant completion, while inventory netting handles the FRAME-S issue.
2. Assembly work center steps. She then adds the real operations that build the cabinet around the sub-frame:

She links the chain (material to assembly to wiring to inspect) and saves. CAB-100 now has a routing that says, in effect, "take one sub-frame, then assemble, wire, and inspect."

Step 3: Schedule and Watch the Levels Resolve

How the two levels schedule depends on whether the sub-frame is stocked. Both paths are worth seeing.

Path A, sub-frame from stock. FRAME-S is a stocked product with 20 on hand. An order for 15 cabinets is scheduled. When the engine hits CAB-100's material step, inventory netting satisfies it from the 20 on-hand sub-frames: 15 are issued, no machine time is scheduled to build them, and the cabinet's assembly step starts as soon as the material is available (immediately, since the stock exists). The Gantt shows only the cabinet's assembly, wiring, and inspection bars; the sub-frame contributes an inventory issue, not a machine bar. This is consume-from-stock netting at work.

Path B, sub-frame built to order. FRAME-S has zero on hand. Now the shortfall must be produced, so a FRAME-S build runs its own saw-and-weld routing first, and the cabinet's assembly step waits until the sub-frames are complete. The engine sequences the producer ahead of the consumer in the same run, so the stock the FRAME-S build creates is visible to the cabinet order that wants it. The Gantt shows the sub-frame's saw and weld bars, then the cabinet's assembly bars starting after them.

Either way, the assembly step never starts before its sub-frame exists. That is the whole promise of a multi-level routing: the parent cannot consume a component that has not been made or netted.

Where the Work Lands (Path B, Illustrative)

For a build-to-order run of 15 cabinets with no sub-frames on hand:

The sub-frame level clears first because the parent's assembly step depends on it through the material link. Cut and weld the frames, then build the cabinets: the engine derives that order from the structure, not from anyone sequencing it by hand.

What This Build Proves

1. A sub-assembly is its own product and routing. Modeling it separately lets you stock it, quote it, and reuse it across parents.
2. The parent references the component as a material step. Blank work center, marked as a product, quantity per parent unit, linked into the chain.
3. Material steps consume components, not machine time. They complete instantly on the machine axis while netting handles the inventory issue.
4. Stocked components net; short components build. Netting satisfies the parent from the shelf when it can, and triggers a build only for the shortfall.
5. The parent never consumes what does not exist. Assembly waits for the sub-frame, and the producer is sequenced ahead of the consumer.

Variations Worth Trying

Stock the sub-frame deliberately. Set a reorder point and reorder quantity on FRAME-S so it replenishes to the shelf on its own cycle, decoupling sub-frame production from cabinet demand. That make-to-stock loop has its own replenishment walkthrough.

Add a third level. If the sub-frame itself consumes a machined bracket that you also make in-house, give the bracket its own product and routing and reference it as a material step inside FRAME-S. The same pattern nests to as many levels as your product needs.

Outsource the sub-frame. If the sub-frame is purchased or sent out, model it with a supplier and lead time, or add transit days on the step so the parent waits the right number of days for it to arrive. Shipping a step out to a plating vendor and back works that transit-days setup through in full, including why inventing a fake work center for the vendor distorts the promise date.

The Bigger Point: Structure Beats a Flattened Routing

Flattening a multi-level product into one long routing works until you want to stock the sub-assembly, quote it, or reuse it, at which point the flattened version fights you. Modeling the real levels, a component with its own routing referenced by a material step, gives the scheduling engine the dependency it needs to sequence build-before-consume automatically, and gives inventory netting the hook it needs to satisfy demand from stock. The structure does the work so you do not have to.

User Solutions has built that discipline into scheduling tools since 1991, for operations with deep product structures: the US Navy, GE, BAE Systems, and Cummins among them. EDGEBIC carries that lineage into a modern engine. If you are moving from an older setup, the complete guide maps the full data model.

Bring your deepest product structure to a demo. Contact us and we will build its multi-level routing against your own data, or read the greenfield setup walkthrough to see a single-level routing built from an empty database first.