Lead Times Tell You More Than Vendor Roadmaps

When a module vendor sends you their roadmap slide for the next eighteen months, they're telling you what they want you to plan around. When the same vendor quotes you a lead time of fourteen weeks for a SKU they claimed to be shipping in volume two quarters ago, they're telling you what's actually happening on their factory floor.

The second number is harder to spin. It comes from operations, not marketing. If you build any forecasting muscle on lead-time intelligence, you'll consistently know more about your vendor's actual position than the salespeople do.

Why roadmap slides systematically lie

The roadmap slide is built backwards from a desired customer commitment. The vendor's product management team decides what they want customers to commit to over the next eighteen months, then constructs a timeline that makes those commitments seem feasible. The timeline is aspirational. The wider the customer's commitment window, the more aspirational the timeline gets.

This isn't dishonesty in the usual sense. It's the standard product-marketing pattern. The same vendor's internal supply chain team, asked the same question, gives you a different answer with smaller error bars. You just don't get to hear that answer.

Lead times leak the supply-chain team's view. A quoted lead time is a commitment the vendor has to honour, or take operational consequences. The number that arrives in your purchasing system is much closer to reality than the number on the roadmap deck.

What lead times leak about fab capacity

Six observations from tracking lead times across the optical industry for several years.

Lead time growth precedes shortage announcements. If a SKU's quoted lead time grows from 8 to 14 weeks over a quarter, you have between four and eight weeks of warning before the vendor publicly acknowledges supply constraint. The first response should be placing an order, not waiting for the press release.

Lead time contraction precedes price reductions. A vendor whose lead times shrink from 12 to 6 weeks is sitting on inventory. They'll cut price within a quarter to move it. The buyer who notices first gets the early discount.

Lead times leak the next-gen launch timing. When a current-generation SKU's lead time shortens dramatically while quotes for the next-gen SKU start appearing with reasonable timelines, the vendor is preparing for a generation transition. The transition is six to ten weeks out.

Vendor-specific lead-time anomalies leak fab capacity allocation. If vendor A's quoted lead times for a SKU class are consistently shorter than vendor B's for the same class, vendor A has more allocation. That tells you something about which vendor will be more flexible on a large bid.

Lead times for sample units vs production units diverge meaningfully. A sample-unit lead time of 4 weeks against a production-unit lead time of 20 weeks means the vendor has not started ramping the line. The production roadmap on the slide is unlikely to hold.

Lead times across distributors versus direct sometimes differ. A direct-vendor lead time of 12 weeks against a distributor's quoted lead time of 8 weeks means the distributor has inventory. That's a buying opportunity that the direct sales team won't volunteer.

Where roadmap slides systematically over-promise

Two product launches per generation, by my count over a decade. Almost every vendor announces their high-end module two quarters before they can ship in any volume. The optimism is structural: the marketing organisation needs to be in the conversation when the customer is planning, and the spec gets locked in based on R&D progress that hasn't yet translated to manufacturing readiness.

The most reliable signal that a launch is real is when the lead time for sample units drops below 6 weeks AND the lead time for small-volume production drops below 16 weeks. Before that point, the roadmap date is theoretical. After that point, it's actually shipping.

Customer-facing salespeople don't know these distinctions. The supply chain team does, and the supply chain team isn't usually in the customer conversation. Asking the salesperson "what's the sample lead time today" gets you data the salesperson has to go research, and the answer is often illuminating.

The two-week rule

A simple operational discipline that has paid off repeatedly: track lead-time data on your top 20 SKUs. Update it every two weeks via routine quote requests. Watch for the changes.

A two-week interval is short enough to catch supply chain shifts before they become public news, and long enough that you're not generating noise. Over time, the dataset becomes its own signal. A sudden 50% increase in lead time across multiple SKUs from one vendor tells you that vendor has a fab capacity issue. A sudden contraction means the opposite.

Most networks I've worked with don't do this. The data is free — every quote request returns a lead time. The discipline of capturing and tracking the lead-time numbers separately from the price numbers is what's missing.

What this means for forecast confidence

The forecasts that have aged best in my own work have used lead-time signals as the primary forward indicator and roadmap slides as the directional flavour. The forecasts that have aged worst trusted the roadmap.

If you forecast a 2027 deployment based on a vendor's roadmap claim of "volume shipments H1 2027" and your operational planning assumed that timing, you're vulnerable to a 6-month slip that you have no early warning system for. If you forecast the same deployment with the addition of "lead-time data must show production-unit lead under 16 weeks by Q3 2026 for our timing to hold", you have a milestone check that the roadmap slide can't deliver.

That milestone check is the difference between forecasts that catch surprises early and forecasts that absorb them late.

The discipline isn't hard

Lead-time tracking is one of those operational practices that takes hours per month to maintain and pays back many times over. It's not glamorous. The intelligence team that does it well doesn't get attention because their forecasts are quietly correct. The intelligence team that doesn't gets attention every time a launch slips and the procurement plan breaks.

Ask the lead time. Write it down. Watch it move. Trust it more than the slide deck.