python-software-project-estimator 0.1.2

Estimate the time and cost of a software project

Software Project Estimator

Installing

Install using pip:

pip install python-software-project-estimator

Usage

Here's an extremely trivial example.

from datetime import date

from software_project_estimator import Project, Task
from software_project_estimator.simulation.monte_carlo import MonteCarlo


task = Task(name="This is the only task", optimistic=10, pessimistic=22, likely=15)
project = Project(name="My Project", start_date=date(2023, 1, 1), weeks_off_per_year=0)
project.tasks = [task]

monte = MonteCarlo(project, 100_000)
results = monte.run()

for day, result in results.items():
   print(f"{day}: {result}")

This will print something like this.

2023-01-17: total=8 probability=8e-05
2023-01-18: total=80 probability=0.00088
2023-01-19: total=352 probability=0.0044
2023-01-20: total=1104 probability=0.01544
2023-01-23: total=3392 probability=0.04936
2023-01-24: total=7744 probability=0.1268
2023-01-25: total=12528 probability=0.25208
2023-01-26: total=18184 probability=0.43392
2023-01-27: total=19776 probability=0.63168
2023-01-30: total=16656 probability=0.79824
2023-01-31: total=11280 probability=0.91104
2023-02-01: total=5672 probability=0.96776
2023-02-02: total=2312 probability=0.99088
2023-02-03: total=712 probability=0.998
2023-02-06: total=184 probability=0.99984
2023-02-07: total=16 probability=1.0

As you can see, the 50% probability mark is somewhere between the 26th or the 27th of January. This is because the end date is actually the first date on which the project is actually finished -- not the last date on which work was performed. Let's take a closer look. task.average tells us that our weighted average outcome should be 15.33 person days. Since we only have one person working on this task and we're working 5 day weeks, you could look at this and say, "This will take a little over three weeks."

Looking at the calendar, out project started on 1/1/2023, which was a Sunday. Also, New Year's day was observed in the US on 1/2. The first day we can actually work is 1/3. MLK Day was observed on 1/16, so that's also a day we don't work in the US. The 15.33 days we're actually working are 1/3, 1/4, 1/5, 1/6, 1/9, 1/10, 1/11, 1/12, 1/13, 1/17, 1/18, 1/19, 1/20, 1/23, 1/24, and 1/25. That means that, at around the 50% probability, the first day we don't work on this project is 1/26.

This is all well and good but, really, do you want to commit to finishing at the 50% mark? You may as well flip a coin to see if you can finish on time. What's important here is the shape of the outcomes. There's close to a 2/3 probability that this project can be completed before 1/27 based on our three--point estimate. This is probably a decent estimate of how long it will take in the real world. What you choose to communicate to the boss is up to you.