Time Booking, Idle Time and Its Causes

Time Keeping (previous section) tells us only how long a worker was present in the factory. It says nothing about what the worker actually did with that time — which job, product, or process the worker's effort was applied to. That second, more detailed record is the function of Time Booking.

Time Booking is the recording of the time a worker spends on each specific job, operation, or process during their period of attendance — the data cost accounting needs to charge labour cost to the correct job/product, and to measure a worker's efficiency job by job.

Methods of Time Booking

• Daily Time Sheet: each worker fills in, at the end of every working day, the jobs worked on and the time spent on each — simple, but relies entirely on the worker's own memory and honesty at day's end.
• Weekly Time Sheet: the same idea extended over a week — reduces paperwork frequency but is even more dependent on the worker recalling job-by-job time accurately.
• Job Card (Job Ticket): one card is created per job/order; as a worker begins and finishes work on that job, the start and stop times are recorded directly on the card itself — far more accurate than a worker's end-of-day recollection, since the record is made at the point the work actually happens.
• Combined Time and Job Card: a single card records both the worker's attendance time (from Time Keeping) and the job-wise breakdown of that time, cross-checking one against the other.

Idle Time

Comparing the total time a worker was present (from Time Keeping) against the total time actually booked to productive jobs (from Time Booking) almost always reveals a gap — hours for which the worker was paid, but which cannot be charged to any job because no productive work was done during them. This gap is called Idle Time.

Idle Time = Time Kept (Total Attendance Time) − Time Booked (to Productive Jobs)

Idle time is not, by itself, a sign of wrongdoing — some idle time is a completely normal and unavoidable part of running any factory. Cost accounting therefore splits idle time into two categories, treated very differently in the cost accounts:

Normal Idle Time

Idle time that is unavoidable, and inherent to the way any factory of this kind operates — examples: the short time lost between one job finishing and the next starting (machine resetting/tool-changing time), tea breaks and the time taken walking from the factory gate to the workstation, the time lost each day while machines are being started up or shut down. Because this is genuinely unavoidable, its cost is absorbed as part of normal production cost — usually included in Factory Overhead, or built into the wage rate charged to jobs via a small upward loading, rather than treated as a loss.

Abnormal Idle Time

Idle time arising from causes that are avoidable, or genuinely abnormal to normal factory operation — examples: a machine breakdown, a power failure/cut, a strike or lock-out, non-availability of raw material due to a supply failure, or faulty production planning/scheduling by management. Because abnormal idle time represents a genuine inefficiency or loss — not a routine cost of doing business — its cost is excluded from the cost of production altogether and instead charged directly to the Costing Profit and Loss Account as a loss for the period.

| Basis | Normal Idle Time | Abnormal Idle Time |

|---|---|---| …