คู่มือโดยละเอียดเร็วๆ นี้
เรากำลังจัดทำคู่มือการศึกษาที่ครอบคลุมสำหรับ Cycle Time Calculator กลับมาเร็วๆ นี้เพื่อดูคำอธิบายทีละขั้นตอน สูตร ตัวอย่างจริง และเคล็ดลับจากผู้เชี่ยวชาญ
Cycle time is the total elapsed time from when work on a unit begins to when that unit is completed and ready for the next stage — or delivered to the customer. It is one of the most fundamental metrics in lean manufacturing and process improvement, forming the basis for capacity planning, takt time comparison, production scheduling, and continuous improvement initiatives. Understanding cycle time enables businesses to answer the essential operational question: how fast can we make or deliver our product? Cycle time can be measured at different levels of granularity. Machine cycle time is the time a machine takes to complete its operation on one part. Operator cycle time is the time an operator takes to complete their work cycle at a workstation. Total cycle time (also called throughput time or lead time) is the end-to-end time from raw material entry to finished goods exit. In lean manufacturing, the goal is to reduce cycle time progressively through waste elimination — removing non-value-adding steps like waiting, transport, and unnecessary motion. Cycle time analysis is directly connected to throughput and capacity. If a machine's cycle time is 30 seconds per unit, it can theoretically produce 120 units per hour (3,600 / 30). If takt time (the rate at which customers demand product) is 45 seconds per unit, the machine has capacity to spare. If takt time is 25 seconds, the machine is the bottleneck — it cannot keep pace with demand and either cycle time must be reduced or a second machine must be added. In service operations and software development, cycle time has evolved to measure the time from when work begins on a task to when it is delivered. In Agile and DevOps contexts, 'cycle time' specifically means the time from when a developer starts coding a feature to when it is deployed to production — a key metric for delivery velocity. Reducing cycle time in knowledge work requires identifying and eliminating blockers, review bottlenecks, and waiting time between process stages.
Cycle Time Formulas: Basic Cycle Time: CT = Total Time per Unit = Net Production Time ÷ Units Produced Or: Time when last unit is complete − Time when first unit started ÷ Units Machine Cycle Time: MCT = Process Time + Load/Unload Time + Any Wait Time at Machine Throughput from Cycle Time: Units per Hour = 3,600 seconds ÷ Cycle Time (seconds) Units per Day = Daily Available Seconds ÷ Cycle Time Cycle Time vs Takt Time: If CT < Takt Time → Capacity available (not the bottleneck) If CT > Takt Time → Bottleneck (cannot meet customer demand rate) If CT = Takt Time → Perfectly balanced (theoretical ideal) Worked Example — CNC Machining Center: Shift: 480 min × 60 sec = 28,800 sec available Parts produced in shift: 540 Cycle time = 28,800 ÷ 540 = 53.3 sec/part Takt time = customer demand rate = 60 sec/part CT (53.3) < Takt (60) → Machine has some capacity buffer
- 1Select the process or operation to measure — define clear start and end points. For machine cycle time: from when the machine closes/starts on a part to when the part exits ready for the next operation. For total production cycle time: from when raw material or components enter the process to when the finished product is ready for shipping.
- 2Measure or observe the cycle time using a stopwatch, cycle time data from a machine control system, or MES (Manufacturing Execution System) timestamps — collect at least 30 observations to account for variability.
- 3Calculate average cycle time and observe the distribution — note the minimum (theoretically achievable) and maximum (worst case) cycle times. High variance in cycle time often signals process instability that is worth investigating.
- 4Compare cycle time to takt time — if cycle time is less than takt time, the operation has available capacity; if cycle time exceeds takt time, it is the bottleneck and limits throughput of the entire value stream.
- 5Identify the components of cycle time: value-adding time (actual transformation of the product), necessary non-value-adding time (mandatory steps like setup, inspection), and pure waste (waiting, transport, rework). Most total cycle times are 90%+ waste when measured from raw material to delivery.
- 6Calculate the impact of cycle time reduction — a 10% cycle time reduction at a bottleneck operation increases throughput of the entire system by approximately 10%, translating directly to higher revenue capacity.
- 7Set cycle time improvement targets based on takt time requirements and document a kaizen improvement roadmap to achieve the target cycle time through waste elimination, standard work, and process redesign.
Station 2 defines the maximum throughput of the entire line. To meet takt time of 50 sec, Station 2 must be improved from 58 to below 50 sec — or work redistributed from Station 2 to Stations 1 or 3 which have available capacity.
Reducing CNC cycle time from 180 to 150 sec (17% reduction) adds 4,000 units/year of capacity at the same fixed cost — worth $60,000 in additional margin. This quantifies the financial value of cycle time reduction projects.
In Agile, cycle time measures from 'started' to 'done'. 24 stories in 10 working days = 2.4/day throughput; avg cycle time of 2.1 days means half of stories take longer — identifying queue buildup or review bottlenecks worth investigating.
The ED's actual cycle time (192 min) is 16× its takt time (12 min) — meaning patients wait 16 hours of process time for every 12 minutes of value-added care. This ratio (typical in healthcare) quantifies the lean improvement opportunity.
Manufacturing engineers use cycle time measurements to balance assembly lines — redistributing work elements between stations so all operators finish within takt time, eliminating bottlenecks and idle time simultaneously, enabling practitioners to make well-informed quantitative decisions based on validated computational methods and industry-standard approaches
Lean practitioners use value stream mapping with cycle time data for each process step to quantify the ratio of value-added time to total lead time — typically finding that 95%+ of total lead time is non-value-adding, revealing the scale of lean improvement opportunity.
Agile teams use cycle time metrics from their project management tools (Jira, Linear, Azure DevOps) to set realistic sprint commitments and identify systematic bottlenecks in their software delivery pipeline, allowing professionals to quantify outcomes systematically and compare scenarios using reliable mathematical frameworks and established formulas
Hospital administrators use ED cycle time analysis to redesign patient flow pathways, identifying steps where patients wait the longest and implementing changes (fast-track lanes, co-location of services, predictive staffing) that reduce total cycle time and improve patient experience.
Batch processing creates a different cycle time dynamic than unit processing —
Batch processing creates a different cycle time dynamic than unit processing — the 'cycle time' for an oven or furnace may be 4 hours to process a batch of 200 parts, giving an effective cycle time per part of 72 seconds. When analyzing batch processes, distinguish between batch cycle time (total time for one batch) and effective per-unit cycle time (batch time / batch size). Increasing batch size reduces per-unit cycle time but increases batch lead time — a classic lean batch size tradeoff.
In multi-product manufacturing environments, cycle time changes with product
In multi-product manufacturing environments, cycle time changes with product mix — a product line switch requires changeover (setup) time that is not counted in cycle time for individual parts but affects effective capacity. When calculating production capacity, distinguish between productive cycle time (the time actually processing parts) and changeover-adjusted cycle time (accounting for the fraction of time lost to setups). SMED (Single-Minute Exchange of Die) targets changeover time as the lever to increase effective capacity.
Cycle time variability is often more operationally important than average cycle time.
A process averaging 60 seconds with a standard deviation of 5 seconds (8% CV) is much more predictable than one averaging 55 seconds with 20 seconds standard deviation (36% CV). High cycle time variance creates queue buildup downstream, WIP accumulation, and unpredictable throughput. Statistical process control (SPC) applied to cycle time data distinguishes common cause variability (inherent process noise) from special cause variability (assignable causes that should be eliminated).
| Process Type | Typical Cycle Time | Bottleneck Source | Key Improvement Lever |
|---|---|---|---|
| Automotive body stamping | 6–15 sec/part | Die close time | Higher tonnage press, lubrication |
| CNC machining (complex) | 2–20 min/part | Cutting parameters, tool changes | CAM optimization, HSM toolpaths |
| Electronic PCB assembly | 15–60 sec/board | SMT placement speed | Higher speed pick & place |
| Software story completion | 1–5 days | Code review queue | Review SLA, pair programming |
| E-commerce order pick | 2–8 min/order | Travel time, location accuracy | Slotting optimization, pick-to-light |
| Hospital ED patient | 90–240 min | Bed availability, MD review | Fast track lanes, predictive staffing |
| Loan application processing | 1–10 days | Document verification | Digital verification, workflow automation |
What is the difference between cycle time and takt time?
Takt time is the rate at which customers demand product — it is determined by customer demand, not by your process. Cycle time is how fast your process actually produces one unit — determined by your operations. If your cycle time equals takt time, you're producing exactly at the rate customers are buying. If cycle time is shorter, you have spare capacity. If cycle time is longer, you're a bottleneck and cannot keep up with demand. Takt time is an external target; cycle time is an internal measurement.
What is the difference between cycle time and lead time?
Cycle time (in manufacturing) typically refers to the time to process one unit at an individual workstation or machine. Lead time (or throughput time) is the total elapsed time from when an order is received (or raw material enters) to when the finished product is delivered to the customer. Lead time includes cycle time at all workstations plus all waiting, transport, and queue time between operations. In lean manufacturing, most total lead time is queue and waiting time (90%+) rather than actual processing time.
How do I reduce cycle time without sacrificing quality?
Cycle time reduction strategies that don't compromise quality: eliminate unnecessary non-value-adding steps within the cycle (unnecessary movements, reaches, repositioning); move sequential steps to parallel processing where possible; redesign fixtures and tools to eliminate positioning time; use quick-change tooling (SMED principles) to reduce setup within the cycle; apply standard work documentation to find and eliminate inconsistencies; and use error-proofing (poka-yoke) to eliminate the need for manual inspection steps that add to cycle time.
What is 'touch time' vs. cycle time?
Touch time (or value-added time) is the portion of cycle time during which the product is actually being transformed — cutting, welding, assembling, coding. Cycle time includes all time from start to end of the work cycle, including non-value-adding elements like loading/unloading, waiting for a previous operation to complete, and operator walking time. The ratio of touch time to cycle time reveals process efficiency: a high touch-to-cycle ratio means little waste; a low ratio means significant improvement opportunity.
How does cycle time affect WIP inventory?
Little's Law connects cycle time to WIP: WIP = Throughput Rate × Cycle Time. If you process 100 units per hour and cycle time is 2 hours, average WIP is 200 units. Reducing cycle time directly reduces WIP, which reduces working capital tied up in process inventory and shortens cash conversion cycle. This is why lean manufacturing's goal of cycle time reduction is simultaneously a financial goal — less WIP means less capital tied up in the production process.
Can cycle time apply to non-manufacturing processes?
Yes — cycle time is extensively applied in service processes, software development, and knowledge work. In healthcare, cycle time tracks patient flow through clinical processes. In banking, it measures loan application processing time. In software (Agile/DevOps), cycle time measures from when a developer starts a task to when it's deployed. The key is defining clear start and end points and measuring the actual elapsed time. Lean and Six Sigma methodologies apply cycle time reduction to any repetitive process.
What is cycle time in Agile/Scrum development?
In Agile and Kanban software development, cycle time is the elapsed time from when a work item enters 'In Progress' status to when it reaches 'Done'. This is distinct from lead time (from when the item is created/requested to when it's done). Cycle time in software measures development execution speed; lead time measures the total wait including backlog queue time. Kanban teams track cycle time distributions to identify bottlenecks (code review, QA, deployment) and set realistic service level agreements for delivery timelines.
เคล็ดลับโปร
Measure cycle time during the first hour and last hour of a shift separately — cycle times often differ due to startup effects (slower at the beginning as operators warm up) and fatigue effects (slower near end of shift) or end-of-shift rushing (faster but potentially lower quality). Understanding within-shift cycle time variation helps schedulers plan realistic daily output targets rather than using a single average.
คุณรู้ไหม?
Toyota's Takt-based production system requires that every workstation on an assembly line has a cycle time that fits within takt time. In the 1990s, Toyota engineers spent months analyzing and documenting the standard cycle time for every single operation in a vehicle assembly — over 30,000 individual work elements — creating the foundation for their famous Standard Work sheets. This meticulous cycle time documentation is why Toyota can consistently produce a vehicle every 57 seconds per plant while maintaining world-class quality.