Describe the work schedule
Set working hours per day, working days per year and the period being assessed.
ELECTRICAL & DUTY / TOOL 29
Mechanism Service-Duty Analysis
Turn an operating schedule into expected mechanism running hours over a defined service period.
Before you start: required inputs
- Choose one mechanism, such as hoisting or bridge travel, and obtain its actual on-time within the scheduled hours.
- For cubic equivalent hours, obtain a time-weighted cubic coefficient consistent with that mechanism’s load definition.
Calculation diagram
A PRACTICAL WALKTHROUGH
How to use this calculator
Separate running from attendance
Set how many minutes the selected mechanism actually runs in each scheduled hour.
Read total operating hours
Compare annual and service-period running time. Treat cubic equivalent hours as a separate weighted quantity.
Hoist running 15 minutes per scheduled hour
THE INPUTS
8 scheduled hours/day, 15 running minutes/hour, 250 days/year, 20 years and a time-weighted coefficient of 0.25.
THE RESULT
Annual running time is 500 h and service-period running time is 10,000 h. Cubic full-load-equivalent time is 2,500 h.
What does the result mean?
01
On-time fraction describes the mechanism’s running share of scheduled hours.
02
Cubic equivalent hours depend on the entered time-weighted coefficient; they are not the same as actual clock hours.
03
ISO/FEM group, inspection interval and remaining safe working life require the applicable classification method and actual history.
Watch for this
Counting the full factory shift as hoist running time even while the hoist is stationary.
Formula & model conditions +
H_operating/year = hours/day × on-minutes/hour ÷ 60 × days/year
H_lifetime = H_operating/year × years
H_cubic-equivalent = k_time × H_lifetime
- A constant schedule and on-time fraction are applied to the full assessed service period.
- The cubic coefficient is supplied by the user and is weighted by mechanism operating time.
- No ISO/FEM mechanism group, design working period, inspection interval or remaining safe life is automatically assigned.
Common questions
Why does this tool not output M1–M8?
Assigning a group requires the applicable standard definitions and classification procedure. This tool keeps the operating-time inputs and arithmetic visible instead.
Can I use one result for every crane mechanism?
Hoisting, trolley travel and bridge travel can have different running times and load histories. Assess each separately.