A four-step method for assessing the production capacity of a machinery factory (Source: Production Management Methods): ① Calculate OEE (Availability × Performance × Quality; world-class standard is 85%); ② Identify bottlenecks (the slowest process determines the plant’s total capacity); ③ Calculate effective capacity (nominal capacity × OEE); ④ Verify the seven key elements (Manpower, Machine, Material, Mold, Site, Technology, Management)—a manufacturer’s claim of “100% capacity” does not equal actual capacity (e.g., if OEE is only 50%, actual capacity is cut in half).
I.
OEE (Overall Equipment Effectiveness)
Formula: OEE = Availability × Performance × Quality (Source: ISO 22400); Availability: Actual operating time / Planned time (deducting breakdowns/mold changes); Performance: Actual cycle time / Theoretical cycle time (deducting micro-stops/speed reductions); Quality: Good units / Total output (deducting scrap/rework); Benchmark: World-class 85% (most factories fall far below this; Source: Fiveable); Usage: OEE is a tool for identifying losses, not just a number for show (Source: SEA)—start by requesting the manufacturer’s OEE data (if they cannot provide it, it implies they lack a clear understanding of their own operations).
II. Bottleneck Analysis
Principle: Plant-wide capacity = Capacity of the bottleneck process (determined by the slowest process; Source: Theory of Constraints); Identification: ① Where material piles up before a workstation; ② Process with a cycle time closest to or exceeding Takt time; ③ Equipment with the lowest OEE (Source: insightfab); Example: Station A at 600 units/shift, Station B at 380 units/shift (bottleneck) → Plant-wide capacity is 380 units (Source: CalcNetra); Improvement: Optimizing the bottleneck is the only effective approach (optimizing non-bottlenecks merely increases Work-in-Progress/WIP)—assess capacity by looking at the bottleneck first (not just counting the number of machines).
III.
Effective Capacity Calculation
Nominal Capacity: Theoretical maximum output; Effective Capacity: Nominal Capacity × OEE (Source: dillygence); Usable Capacity: Effective Capacity × First Pass Yield (FPY); Manpower Capacity: Number of staff on duty × Shift duration × (1 – Allowance rate of 10–15%) × Overall efficiency (Skilled worker: 0.95 / New worker: 0.85); Scheduling Principle: Reserve a 15–20% buffer for core equipment (to handle rush orders and breakdowns; Source: Capacity Analysis)—buyers evaluate delivery dates based on “Effective Capacity” (not Nominal Capacity).
IV.
Seven Elements of Capacity
Manpower: Effective operational capability (not just headcount); Machines: OEE headroom + bottleneck machines; Materials: Kitting completeness rate (missing parts = line stoppage); Tooling/Molds: Avoid letting a single mold set constrain the entire plant; Space: Full space = zero capacity; Technology: Engineer speed can also be a bottleneck; Management: Slow information flow = capacity loss (Source: Seven Elements of Capacity Analysis)—if any of the seven elements is lacking, capacity is compromised (evaluate each item individually).
V. On-site Assessment Methods
Observe the workshop: Equipment utilization rate (running vs. idle); Ask for data: OEE, mold changeover time, failure rate, scrap rate; Check inventory: Areas where work-in-progress (WIP) accumulates indicate bottlenecks; Check shifts: Single, double, or triple shifts (single-shift operation leaves two-thirds of machine capacity idle); Check orders: Current orders in production plus the production schedule;
Check reports: Daily production reports and yield records—prioritize actual data over promotional claims (cross-verify on-site observations with reports).
VI. Application of Assessment Conclusions
First, determine delivery dates: Calculate based on effective capacity (not nominal capacity); second, set MOQ: Determine order volume based on monthly capacity; third, prevent overselling: Maintain a capacity buffer when placing orders across multiple factories simultaneously; fourth, discuss improvements: Raising OEE from 65% to 80% yields 23% more output from the same equipment (Source: CalcNetra);
fifth, decide on partnerships: Capacity reliability reflects supplier maturity—for machinery and equipment factories, assess capacity via OEE, bottlenecks, and the “seven elements” (Effective Capacity × Buffer Margin = Reliable Delivery Date).
