Source Data

• Using the Human Error Rates in a previous post.
• Example - github.com - Creating a pull request from a fork

Process

1 - List the steps

1. Navigate to original repository
2. Right of the Branch mean, click New Pull Request
3. On the Compare page, click compare across forks
4. Confirm base-fork and base-branch
5. Use head fork to select fork, compare branch to select branch
6. Type a title and description for your pull request
7. If you do not want to allow upstream edits, unselect Allow edits

2 - Classify the steps and add error rates

Steps	Classification	Error rate
1. Navigate to original repository	Routine, familiar	0.0004
2. Right of the Branch mean, click New Pull Request	Routine, instruction	0.0060
3. On the Compare page, click compare across forks	Routine, instruction	0.0060
4. Confirm base-fork and base-branch	Non-routine, instruction	0.0300
5. Use head fork to select fork, compare branch to select branch	Non-routine, instruction	0.0300
6. Type a title and description for your pull request	Routine, familiar	0.0004
7. If you do not want to allow upstream edits, unselect Allow edits	Routine with deviation	0.0160

3 - Add success rate

Steps	Classification	Error rate (pError)	Success Rate (1 - pError)
1.	Routine, familiar	0.0004	0.9996
2.	Routine, instruction	0.0060	0.9940
3.	Routine, instruction	0.0060	0.9940
4.	Non-routine, instruction	0.0300	0.9700
5.	Non-routine, instruction	0.0300	0.9700
6.	Routine, familiar	0.0004	0.9996
7.	Routine with deviation	0.0160	0.9840

4 - Calculate probability of success

Take the product of the success rates to find to likelihood of all steps being completed successfully.

In Excel, Google Sheets,

=ROUND(PRODUCT(pSuccess1:pSuccess7), 2)

For this sequence of steps the likelihood of success is 0.91, or 91%.

Apply for number of likely iterations (e.g. 10) using

=BINOMDIST(10, 10, .91, FALSE)

Example

Download example spreadsheet,

• OpenDocument Spreadsheet
• Excel

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