Project scoping
For solar-accessory procurement, choose the development route by what is already defined and what still has to be designed. Use an OEM-style brief when you have a controlled design to build; use an ODM-style brief when an existing supplier platform is the starting point. Suppliers use these labels differently, so write the actual design, verification and delivery responsibilities into the RFQ.
Compare the work behind the label
| RFQ question | Buyer-defined design | Existing supplier platform |
|---|---|---|
| What is the starting point? | A drawing, bill of materials and revision, plus clearly identified gaps. | An exact platform model and the proposed differences from it. |
| What may change? | Only agreed changes to the controlled design. | List the features that are configurable and those requiring design review. |
| Who resolves an interface problem? | Identify the buyer's design decision maker and the supplier's review contact. | Ask who controls the platform and approves interface changes. |
| What must samples demonstrate? | Conformance to the agreed drawing and project acceptance criteria. | Conformance to the selected platform plus every approved modification. |
| What costs need separating? | Engineering, tooling, samples, documentation and production units. | Platform units, adaptation, tooling if needed, samples and packaging. |
Neither route automatically means a lower MOQ, shorter lead time or ownership of the underlying design. Ask who owns or may use drawings and tooling, what deliverables you receive and what happens when a revision is introduced. Resolve these project questions before treating two offers as equivalent.
Classify changes before requesting a price
Use a change list with three columns: the original feature, the requested feature and the evidence needed before release. A label or packaging change needs artwork and identification checks. A cable-length change needs a revised drawing and application review. A connector, material or mounting-interface change may need new compatibility, performance or installation evidence. The required review depends on the actual product; a change should not be called “cosmetic” just because it is easy to order.
Illustrative example: two suppliers quote a branded battery cable. One keeps the original cable and terminals and changes the label. The other changes cable length and terminal geometry as well. These are different scopes. Compare them only after the changed interfaces, evidence and sample requirements have been made explicit. This example is a procurement method, not a measured cost saving or customer case.
Why model-specific evidence matters
Victron's Lithium Battery Smart installation instructions distinguish terminal thread and tightening requirements by battery model. This is a useful example of why a familiar connection size does not justify copying assembly instructions from another product. For a proposed accessory change, request the instructions for the actual equipment interface; do not apply Victron values to an unrelated SINAWATTS part.
If certification is part of the purchase requirement, identify the exact model and supporting record. UL Solutions' Product iQ information page explains how its database supports certification checks. A record for an original platform does not, by itself, demonstrate coverage of every requested variant. Ask the certificate holder to establish the applicable scope before making a claim about the modified item.
Use four project decisions
- Scope agreed: the base model or drawing, changes, quantities and unresolved questions are recorded.
- Feasibility reviewed: the responsible parties identify interface limits, evidence gaps, tooling and documents needed.
- Samples accepted: sample identity and revision match the agreed criteria, with exceptions recorded rather than assumed away.
- Production released: the purchase specification, packaging, identification and change-notification requirements refer to the accepted revision.
For a cable project, attach the cable assembly RFQ checklist. For a repeat order or a proposed substitute, use the first-article and change-control guide to frame the records to request. These are buyer checkpoints, not a promise that a supplier already has every capability or document.
Separate project cost from unit price
Ask the quotation to distinguish non-recurring work from production units: design review, sample preparation, tooling, artwork, packaging, verification and documentation. State whether the sample and production offers cover the same revision. For timing, identify the dependencies, such as final drawings, approved samples or agreed material selection. Confirm the schedule against that scope rather than relying on a generic website lead time.
A useful comparison sheet has one row for each deliverable and one column for each supplier. Mark missing items explicitly. Do not rank an offer that includes tooling and qualification work against one that quotes only the existing catalog item without accounting for the difference.
Prepare the first enquiry
- Product category and intended application.
- Existing part number or drawing with revision, if available.
- Required changes and the features that must remain fixed.
- Equipment interfaces, destination market and required evidence.
- Sample and production quantities, identification and packaging.
- Open decisions about documents, tooling, design responsibilities and timing.
See SINAWATTS OEM/ODM sourcing support for project inputs and coordination. The suitable production route, verification work, MOQ and delivery terms require project-specific confirmation.
Send an OEM / ODM project brief
Frequently asked questions
Is ODM always faster or cheaper than OEM?
No fixed comparison is reliable without matching the scope. An existing platform can still require interface changes, tooling, sample review or additional documentation.
Can I put my logo on a product and assume the existing certification still applies?
Do not assume coverage. Identify the exact product and proposed changes, then obtain the applicable evidence from the responsible certificate holder.
What can I send if I do not have a finished drawing?
Send the application, reference part or photographs, equipment interfaces, intended changes and quantities. Mark unknown requirements explicitly so the next step is a scoped review rather than a guessed specification.