Steel Fabrication Shop Scheduling and Capacity Planning

Why Tons Per Week Is a Poor Capacity Number

Many shops plan capacity in tons per week because it is easy to track. But 100 tons of simple beams with shear tabs is a very different load from 100 tons of heavy moment frames with CJP flange welds. Capacity should be planned in hours by work center: beam line, plate processing, fit-up, welding, grinding, inspection, paint, and loading.

Convert each release package to hours using labor standards, then sum against available hours after allowing for absenteeism, overtime limits, and rework. The tons-per-week figure becomes a result, not an input. Shops that switch to hour-based loading usually find that welding or fit-up is the real constraint even when the saw looks busy.

• Load by work center hours, not total tonnage
• Include rework and inspection hold time in each package
• Treat the overhead crane as a work center with its own capacity

Release Packages, Drawing Approval, and Material

A schedule is only as good as its inputs. Detailing and drawing approval gate fabrication, so a job cannot enter the shop until approved-for-fabrication drawings are released. Material availability is the next gate: mill lead times on large sections or plate can run weeks, and a service center may not have the heat you need.

Release packages are typically broken to match erection sequence, so the first pieces on site are fabricated first. When approvals slip, the shop should have lower-priority work ready to fill the gap. Without visibility into drawing status, scheduling becomes reactive and idle time rises.

• Track approval status and revision by package, not by job
• Show material arrival dates against planned cut dates
• Keep a buffer of ready work to cover approval delays

Painting, Galvanizing, and Outside Processing

Finishing often controls delivery. Hot-dip galvanizing has its own queue and turn time at the galvanizer, plus restrictions on piece size and venting requirements that must be considered in detailing. Shop paint needs cure time and enclosed space.

Blasting capacity may be shared. If outside processing is not in the schedule as a real step with a lead time, promised ship dates will be fiction. Include transit time and the risk of rework after inspection, such as touch-up or re-galvanizing.

Finite Scheduling in Your ERP

Fabricators often schedule in Excel or on a whiteboard. That works until load grows. ERPs such as SyteLine include finite capacity scheduling by work center, but they require accurate routings, labor standards, and calendars to produce reliable dates.

Fabrication-specific tools track marks and statuses but may be weaker at forward-looking capacity. Pick one source of truth for shop status and one for capacity loading. The common failure is a beautiful schedule in the system that nobody trusts because piece status is updated late.

Where AI Can Help and Where It Cannot

AI can read status, hours, and approval data in your ERP and answer planning questions in plain language: which packages are at risk of missing their ship date this week, what welding hours are loaded for next Thursday, which jobs are waiting on material. It can compare planned to actual cycle times by work center to find the recurring delay. It cannot know that a key welder is out unless that data exists, and it should not reschedule jobs without a planner's approval.

If your shop has a single owner who keeps the schedule in his head and it works, formal tooling may add little.