# How to Estimate Engineering Hours for Custom Machinery Projects > Source: https://netray.co/resources/how-to-estimate-engineering-hours-for-custom-machinery > Publisher: Netray (netray.co), AI and integration engineering for ERP and manufacturing systems. > Section: Knowledge Base ## Short answer How machine builders estimate mechanical, controls and software engineering hours for custom equipment quotes, and how to stop under-quoting design labor. ## Category erp-general ## Content **Intro:** To estimate engineering hours for custom machinery, break the machine into modules, estimate mechanical design, electrical design, controls programming, and documentation hours per module from comparable past jobs, then add a project management and rework allowance. The mistake most builders make is pricing design hours from memory. Actual hours from closed projects, grouped by module type and complexity, give a defensible range instead of a guess, and the gap between that range and the hours you quoted is where ETO margin disappears. **Sections:** #### Why Engineering Hours Are the Biggest Estimating Risk **Body:** On an engineer-to-order machine, purchased components and fabrication are fairly predictable because you can get supplier quotes. Engineering is not. A custom assembly cell can carry 600 to 3,000 engineering hours spread across mechanical design in SolidWorks or Inventor, electrical schematics in EPLAN or AutoCAD Electrical, PLC and HMI programming, robot integration, and safety validation. Those hours get consumed by customer revisions, vendor data that arrives late, and interference found during build. Because they are salaried or at least not purchased per job, they rarely get tracked against the quote, so the same underestimate repeats on the next machine. **Bullets:** - Design hours are usually the least tracked cost on the job - Customer spec changes after PO inflate hours without a formal change order - Controls and software hours are often quoted as one lump with no module breakdown - First-of-a-kind modules carry real research and prototype time that quotes omit #### Break the Machine Into Estimable Modules **Body:** Do not estimate a machine as one number. Decompose it into modules a designer would recognize: frame and guarding, infeed and outfeed conveyance, the process station (press, weld, dispense, inspect), pick and place or robot cell, pneumatics, electrical panel, and operator interface. For each module record mechanical hours, electrical hours, controls hours, and documentation hours, and tag it as repeat, modified, or new design. A repeat module may need only 20 percent of its original hours for adaptation. A new module should carry its original-style hours plus a contingency, since nobody has solved it in your shop before. **Bullets:** - Tag every module repeat, modified, or new - Carry controls and HMI hours separately from mechanical - Include FAT documentation, manuals, and spare parts lists as their own line - Add a distinct line for project management and customer meetings #### Use Actual Hours From Closed Jobs, Not Memory **Body:** The most reliable input is a table of closed projects: module type, complexity rating, estimated hours, actual hours by discipline. Pull it from project labor in your ERP, whether that is Epicor Kinetic project management, Infor SyteLine project accounting, NetSuite SuiteProjects, or Infor VISUAL, or from timesheets if engineering time is booked outside the ERP. Then compute actual-to-estimate ratios per module type. If conveyors consistently run 1.3 times estimate and controls run 1.6 times, apply those ratios to the next quote instead of arguing about whether this one will be different. Revisit the ratios every few closed jobs. #### Where AI Helps Without Replacing the Estimator **Body:** A private AI layer over your ERP and project files can find the five or six past projects most similar to the one you are quoting, pull their module hours, and flag where the new request differs: a larger envelope, a tighter cycle time, a safety category you have not built to before. It can read the customer specification and list requirements that historically drove extra hours, such as vision inspection, serialization, or washdown design. It should draft the hour table with citations to the source jobs. The senior engineer still sets the number, because judgment about this customer and this schedule is not in the data. #### When a Spreadsheet Is Enough **Body:** If you build a few machines a year, each substantially different, the history is too thin for ratios to mean much, and a disciplined spreadsheet with module lines plus a senior engineer review is the right tool. Spend the effort instead on capturing actual hours consistently so ratios become useful after fifteen or twenty closed projects. Where AI or analytics start paying for themselves is when you quote many variations of a product family and carry an estimating backlog. **Cta:** If you want to see how past project hours in your ERP could ground your next engineering estimate, Netray can run a read-only pilot against a copy of your data. **Faq:** #### How many engineering hours does a custom automation machine take? **Answer:** It varies widely with scope, but simple single-station machines can run a few hundred hours while multi-station assembly or inspection systems with robots and vision often run well over a thousand across mechanical, electrical, and controls. The only number that matters for your quote is your own actual history by module type, which is why tracking hours by discipline matters. #### Should engineering hours be quoted as a separate line item? **Answer:** Many builders fold engineering into the machine price, but showing it separately helps with change orders. When a customer revises the spec, a visible engineering rate and hour basis makes the cost of the change easy to explain. For competitive bids you can still present one price while keeping the line items internally. #### How do I track engineering hours against a quote? **Answer:** Create project tasks per discipline and module in your ERP or project tool, require engineers to book time to those tasks weekly, and compare to the quote at milestones such as design freeze. Reviewing at design freeze, not at shipment, is early enough to raise a change order or adjust the build plan. ## Related Slugs - engineer-to-order-erp-challenges - syteline-project-profitability-reporting - erp-cad-integration-engineering-data - multimodal-rag-engineering-drawings-guide ## Search terms how to estimate engineering hours custom machinery, engineering hours estimating machine builder, special machine quoting engineering labor, estimating design hours custom automation, ETO quoting engineering time, custom machine cost estimating --- Talk to an engineer: https://netray.co/contact?intent=erp_ai | Machine catalog: https://netray.co/agent/catalog.json