Does the night shift really produce less?
You rarely get to rerun Tuesday. With exactly one measurement per combination, two-factor ANOVA without replication still separates the row effect from the column effect, it just cannot see interactions.
Words on this sheet
- Production line: One of the parallel lines being compared. Each is a separate machine or crew, so a reading from one is not a reading from the other.
Operations Starter Statistics free
After you install, this is the model to open.
Shift or Line: What Moves Output?
- In your spreadsheet, click the Sortia icon in the strip of icons down the right-hand edge. No strip? Click the arrow at the bottom-right to open it. You can also use Extensions, then Sortia, then Open Sortia.
- Click Start from a template and put that name in the search box.
- Pick the card with that name and click Load this template. It arrives on a new tab with real numbers already in it.
The answer
Both factors clear the bar comfortably:
- Shift
- F 316.75 p 0.00004
- Line
- F 187.75 p 0.0001
- Pattern
- consistent all rows and columns
Morning beats evening beats night on every line, and Line 1 beats Line 2 beats Line 3 on every shift; that consistency is exactly what the no-replication design depends on. If you suspect the night crew struggles only on Line 3, that is an interaction, collect repeats and use the with-replication version. Region by quarter, teacher by class, machine by day: same grid.
The model
Units produced in one day, three shifts down the rows, three lines across the columns, one count per cell, from 142 at the best corner to 118 at the worst.
| Grid | 3 shifts x 3 lines |
| Best cell | Morning, Line 1: 142 units |
| Worst cell | Night, Line 3: 118 units |
| Shift effect | calculated |
| Line effect | calculated |
Once it is in your sheet
- The model arrives with real numbers in it and runs as it stands, so you can press the button first and understand it second.
- Change the numbers to yours. The sheet marks which cells are inputs and which hold formulas, and most labels carry a note explaining the row.
- Press the run button at the bottom of the panel. It is labeled for the tool you are in, and the result lands on its own tab, with a written reading of it beside the figures.
Never used Google Sheets? Start here goes the whole way, in seven steps, and assumes nothing.
Next question
- Is one line underfilling, or is that just spread?Are Two Fill Lines Filling the Same?
- Two machines, same average. Which one wanders?Is the New Machine More Consistent?
- What is next month's demand, give or take?Smooth the Noise, See the Trend
- Is overselling worth the bumps at the gate?How Many Tickets Should You Oversell?
- How often will the reserve you set fall short?Is the Warranty Reserve Enough?
- How many people will the peak month need?Staff for the Season, Not the Average
Every model like this one, and the method behind them: Statistics in Google Sheets.
The method behind this one, worked end to end: ANOVA in Google Sheets.