Assembly line balancing calculator with takt time

Takt time, station loading, line efficiency and balance delay for a task list with precedence.

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	A	B	C	D	E	F	G	H	I	J	K
1	Assembly line balancing with takt time
2	Example data — replace the blue input cells with your own.
3	Blue cells are inputs. Takt = net available seconds per day / demand per day.
4	TAKT TIME (S PER UNIT)		MINIMUM STATIONS		STATIONS USED		LINE EFFICIENCY
5	45.0		4		4		90.9%
6
7	Takt time					Line balance
8	Available time per shift (min)		480			Total work content (s)			160
9	Breaks per shift (min)		30			Theoretical minimum stations			4
10	Shifts per day		2			Stations used			4
11	Demand per day (units)		1,200			Longest station time (s)			44.0
12	Net available time per day (min)		900			Line efficiency			90.9%
13	Takt time (s per unit)		45.0			Balance delay			9.1%
14						Precedence and takt checks			OK: no precedence or takt problems
15	Task table (60 rows; one row per task)
16	Task ID	Description	Task time (s)	Predecessor 1	Predecessor 2	Station	Station of predecessor 1	Station of predecessor 2	Precedence check	Cumulative station time (s)	Cumulative check

Showing the first 16 of 77 rows and 11 of 11 columns. Cells with formulas show the formula on hover.

	A	B	C	D	E	F
1	Station loading against takt time
2	Station time adds the task times from the Line tab for each station number. Stations 1 to 15 are listed.
3
4	Takt time (s per unit)			45.0
5
6	Station	Tasks	Station time (s)	Idle time vs takt (s)	Utilization	Status
7	1	3	38.0	7.0	84.4%	OK
8	2	3	35.0	10.0	77.8%	OK
9	3	4	44.0	1.0	97.8%	OK
10	4	4	43.0	2.0	95.6%	OK
11	5	0				No tasks
12	6	0				No tasks
13	7	0				No tasks
14	8	0				No tasks
15	9	0				No tasks
16	10	0				No tasks

Showing the first 16 of 24 rows and 6 of 6 columns. Cells with formulas show the formula on hover.

	A
1	Assembly line balancing with takt time
2	Notes: what this workbook does, how to use it and the method behind it.
3
4	What it does
5	Calculates takt time from available time and demand, then checks a task-to-station assignment for precedence and for station time against takt.
6	The Line tab holds the takt inputs and the task table. The Stations tab adds up task times for each station number and compares each station with takt.
7	The example data is fictional: a small appliance assembly with 14 tasks on 4 stations.
8
9	How to use it
10	1. On the Line tab, enter the available time per shift, breaks, shifts per day and demand per day.
11	2. Type each task ID, description and task time in seconds. Add up to two predecessor task IDs, or leave them blank.
12	3. Enter the station number for each task in the blue Station column.
13	4. Read the Precedence check and Cumulative check columns, and fix any task marked with a flag.
14	5. Read line efficiency and balance delay on the Line tab, and station status on the Stations tab.
15
16	Formulas and method

Showing the first 16 of 35 rows and 1 of 1 columns. Cells with formulas show the formula on hover.

What does this template do?

Line balancing shares an assembly task list across workstations so that every station finishes its work within the takt time. This workbook is for industrial engineers and line supervisors who lay out an assembly line or test a new task assignment.

Takt time is net available time per day divided by daily demand, in seconds per unit. Each task has a time, up to two predecessors and a station number. The Line tab looks up the station of each predecessor and flags any task that sits before a predecessor. A running total of station time is compared with takt for each task.

The Stations tab adds up task times for each station, shows idle time and utilization, and marks stations over takt. Line efficiency is total work content divided by stations used times the longest station time, and balance delay is one minus efficiency. The example data is fictional: fourteen tasks for a small appliance.

What’s inside

Takt time from available time, breaks, shifts and daily demand
Predecessor stations checked against each task's station
Running station time checked against takt for every task
Station loading for up to 15 stations, with idle time and utilization
Line efficiency and balance delay from total work content and the longest station

Which tabs does the workbook have?

Tab	What it holds
Line	Takt inputs, the balance summary and the task table with precedence and cumulative checks.
Stations	Station time, idle time, utilization and status for stations 1 to 15.
Notes	What the workbook does, the formulas in words, assumptions and limits.

What formulas does this template use?

This template holds 396 formulas in 562 cells across 3 tabs, so 70% of its cells calculate. They use 15 distinct functions; the longest formula is 232 characters and 34 of them read from another tab.

Function	Uses	What it does
`IF`	863	one result when a test is true, another when false
`INDEX`	240	value at a position in a range
`MATCH`	240	position of a value in a range
`OR`	180	true when any test is true
`AND`	121	true when every test is true
`IFERROR`	120	swaps an error for a fallback value
`ISNUMBER`	120	true for a number
`SUMIF`	75	adds values meeting one condition
`COUNTIF`	19	counts cells meeting one condition
`SUM`	5	adds numbers
`COUNT`	2	counts numeric cells
`COUNTA`	1	counts non-empty cells

The 12 most used of 15 functions. Counted from the workbook itself. Only functions that Excel, LibreOffice Calc, Google Sheets and Apple Numbers evaluate the same way are used, so the formulas survive every download format.

How do you use it?

Enter available time, breaks, shifts per day and daily demand on the Line tab to get takt time.
Type each task with its time in seconds and up to two predecessor task IDs.
Assign each task to a station number in the blue Station column.
Read the Precedence check and Cumulative check columns, and fix any task marked with a flag.
Read line efficiency, balance delay and station status on the Line and Stations tabs.

What is it good for?

Balancing a small appliance assembly line
Checking whether a proposed station layout meets takt
Estimating the stations needed for a new demand level
Comparing two task assignments before a layout change

Questions about this sheet

What is takt time?

Takt time is the available working time divided by customer demand, so it is the pace a line must keep to meet demand. The sheet gives it in seconds per unit.

What does the precedence check test?

It tests whether each task's predecessors sit at its own station or at an earlier one. A task whose predecessor sits at a later station is flagged as Precedes a later station.

How is line efficiency calculated?

Line efficiency is total task time divided by the number of stations used multiplied by the longest station time. Balance delay is one minus that efficiency.

Does the workbook search for a better station assignment?

No. It checks the assignment you enter against takt and precedence, and it does not search for a better one.