When does your rollout actually reach 80% adoption?
Most change plans carry a date that was picked, not calculated. This model grows adoption month by month from leader push and peer proof, holds peer influence back until the early adopters clear the chasm, and returns the crossing month as a range with a stall probability attached.
Words on this sheet
- Coefficient: How much the outcome moves for each one-unit rise in this input, holding the other inputs still.
Work Advanced Monte Carlo Pro engine
After you install, this is the model to open.
How Long Until the Team Works the New Way?
- 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.
This one runs on a Pro engine, and every free install includes five full-quality runs on your own numbers, shared across all five Pro engines rather than five for each. After that, Pro is $199/year.
The answer
One run gives you two distributions: the month adoption crosses 80%, and how far along the rollout is at the 12 month checkpoint.
- Median time to 80% adoption
- 17 months
- Chance of 80% inside 12 months
- 6 %
- Chance 80% never lands inside 24 months
- 22 %
- Adoption at month 12, P10 to P90
- 41 to 78 %
The median rollout needs 17 months to reach 80% adoption, and only 6% of trials get there inside a year, so a plan that promises full adoption in two or three quarters is betting on the top few percent of outcomes. 22% of trials never reach 80% at all within 24 months, and most of those fail because the ceiling on who will ever adopt sits below the target rather than because the curve was slow. At the 12 month review the middle 80% of trials sit between 41% and 78% adopted, which tells you what a healthy mid rollout number looks like before you decide to intervene.
The model
A 200 person rollout of a new way of working, with four uncertain drivers and a 24 month horizon.
| Employees in scope | 200 |
| Leader push coefficient p (comms, training) | 0.012 – 0.025 – 0.050 (uncertain) |
| Peer influence coefficient q (visible wins) | 0.20 – 0.32 – 0.48 (uncertain) |
| Chasm drag on peer influence | 0.10 – 0.30 – 0.65 (uncertain) |
| Chasm ends once adoption reaches | 16% of employees |
| Maximum reachable adoption (ceiling) | 70% – 88% – 98% (uncertain) |
| Adoption target | 80% of employees |
| Horizon | 24 months |
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
- What would regret have to be worth to leap?Should You Take the Career Leap?
- How do you give every team a fair share of every skill?Balanced Team Builder
- Is there a deal that beats splitting the difference?Win-Win Deal Finder
- Will your walk-away price leave any deal zone at all?Deal Zone Odds (ZOPA Simulator)
- What finish date can you actually commit to?What Finish Date Can I Commit To?
- How much buffer does this plan actually need?How Much Buffer Does This Plan Need?
Every model like this one, and the method behind them: Monte Carlo simulation.