The output caliber needs to bring the product mix
"How many tons per shift" should also give the steel type, cross-section, beam length, single piece weight, welding workload, shift and qualification standards. The same ton of steel can be a small number of heavy beams or more light beams; the number of loading times, weld length and adjustment workload are different. The tonnage target cannot be directly converted into the number of machines.
Divide representative product groups according to cross section, welding volume, beam length and batch size, and record the proportion of each group. A typical week's or month's worth of orders may be used for the initial evaluation, with special orders listed separately. This avoids taking the demonstration speed of a workpiece that is easiest to process as the entire factory output.
Route comparison first meets the welding requirements: split flat-position fillet welding is suitable for heavy steel, and can use bevel, multi-layer, multi-pass welding; this process does not have an upper limit of thickness of single wire without bevel 16 mm or double wire 24 mm, and is actually constrained by equipment, workpieces and WPS. The upper limit of web full penetration for 45° fillet welding of the integrated machine is 14 mm, and groove expansion is not supported. Different passes and joint workloads cannot be directly compared in tons/shift.
Complete cycle includes machining and auxiliary operations
The complete cycle includes processing, loading and unloading, positioning adjustment, turning, process assistance, inspection and reasonable allocation of model changes. Reasons for waiting should be recorded separately: waiting for overhead crane, lack of materials, downstream space occupation and equipment failure, corresponding to different improvement methods. Don't lump them all into slow machines.
| Work station | Processing part | Auxiliary jobs recorded simultaneously |
|---|---|---|
| Sectional cutting | Cutting time corresponding to actual path and process | Steel plate loading and unloading, perforation, setting, material sorting and remaining material processing |
| assembly tack welding | positioning, clamping, tack welding | Complete set loading, calibration, inspection, changeover and transfer out |
| Longitudinal seam welding | Actual welding of each pass for each weld | Position turning, start and stop arc, welding flux and inter-layer operations, inspection |
| 翼緣矯正 | Number of passes and actual feed | Setup, support, loading and unloading, and geometry review |
| shot blasting cleaning | Transit time to achieve agreed surface requirements | Loading distance, loading and unloading, cleaning inspection and rework |
Use load meter to compare work stations, not just speeds
For each product group, multiply the planned number of pieces by the complete cycle of the unit to obtain the number of minutes that the group occupies a certain station; after adding up each group, add the unallocated changeover operations. Available time is deducted from planned breaks, maintenance and other non-production periods, and whether personnel can serve multiple workstations at the same time must also be checked.
Station load rate = planned number of station minutes required ÷ number of available station minutes. More than 100% means that the plan cannot be completed under the current assumptions; below 100%, shared overhead cranes, transfer conflicts and cycle fluctuations still need to be checked.
Employment accounting should also record the actual occupation of each position and whether operators are shared. Split workstations can be organized in parallel, and integrated machines can reduce some intermediate handling, but both need to cover loading and unloading, turning, inspection and exception handling; you cannot commit to a fixed number of people or a reduction ratio before there is no job measurement.
Why can’t welding speed be directly converted into output?
The pure welding time can be estimated by dividing the length of each weld by the corresponding speed, but the number of welding heads, simultaneous working welds, number of passes and actual position must first be clarified. Only tasks that are actually carried out at the same time can be calculated in parallel; welds that can be welded after turning cannot be regarded as completed at the same time.
The welding travel, idle travel and straightening feed in the quotation belong to different working conditions. Using idle speed to calculate welding, or omitting start and end sections, changeovers and inspections will overestimate the finished product output. Before the process and qualification rate are verified, the cycle cannot be shortened by simply increasing the operating speed.
After finding the limitations, choose the improvement action
| On-site phenomenon | First check | Possible improvements |
|---|---|---|
| The equipment is idle and the supply is unstable | Set allocation, batch sequence and material identification | Adjust the supply plan and buffer position |
| Loading and unloading contention overhead crane | Sharing overhead crane actions and time distribution | Off-peak loading or evaluation of auxiliary transshipment |
| Frequent machine adjustments take up working hours | Product sorting, positioning methods and model change steps | Schedule production according to similar specifications and standardize setting records |
| Welding at full load for a long time | Joint requirements, passes and effective welding time | Evaluate configuration or parallel workstation after quality conditions are established |
| Repeat straightening or cleanup rework | Upstream deformation, loading and acceptance conditions | First improve the incoming material process, and then check the equipment capabilities |
Backfill real production data after trial run
- Use representative product groups from the original evaluation, without temporary substitutions for workpieces that are easiest to machine.
- Record processing, auxiliary, waiting, downtime and rework times respectively.
- Synchronously record personnel, configuration, number of passes, shifts and quality results.
- Backfill the load table with actual cycles and recheck bottlenecks and buffering requirements.
- Technical documents distinguish between guaranteed values, reference estimates, and conditions to be verified.
日期為本次預覽的擬定編輯排程，不代表過往實際發布日期。