Optilogic jules 1

Series: Using Optilogic For Everyday Scenarios

Using Optilogic for Family Budgeting

It’s almost 2021 and the Carson family is ready to start the new year off on the right foot. They want to budget for the entire year so they can do the following:

  1. Be prepared for monthly and yearly expenses such as rent, grocery, and auto maintenance.
  2. Optimize their budget to visualize how much they can spend on leisure activities depending on different scenarios.
  3. Ensure that they’re cutting out extra costs and putting that money towards savings.

Jules Carson, the eldest daughter of the Carson family, studies Industrial & Operations Engineering at the University of Michigan. Well practiced in Python and data modeling, she knew that there’s an easier and more accurate way to plan her family’s 2021 budget than using Microsoft Excel like they had in the past.

How Jules used Optilogic

Before starting, Jules inventories the data she’ll need to work with. This data includes details about her family’s income and spending habits that would help her create a budget that fits her family’s lifestyle. She asks the members of her family to answer the following:

  • What is the net income per month for the family?
  • How many payments are made per year towards rent/utilities, how many times are these payments made and in what amount?
  • What is the monthly income from the state allowance?
  • What’s the minimum the family wants to spend on fun activities each month?

With this information, Jules fires up Optilogic. “There’s a model for everything!” Jules thinks to herself as she searches through Optilogic’s Model Library. She comes across the Family Budget model, a pre-configured model where she would simply need to add her data inputs in her workspace. Each model comes with explainer documentation that can be accessed within any workspace of how the model was formulated mathematically. While the mathematical formulation of models is not Jules’s expertise, she could still understand how and why the model was constructed the way that it was, and why it’s a good fit for her to use for her family’s budgeting.


P.S. Just like Jules, you can see the mathematical breakdown of this very same model. Create an account here and jump into the Family Budget model.

Create An Account


Because the Family Budget model is already implemented within the model library, Jules simply copies the model into her workspace so she can start using the model with her specific inputs. She takes a quick look at the variables and constraints that the model incorporates.

Model Data 1

She sees that the model contains parameters that account for most of the data she’d like to input:

  • What is the net income per month for the family?
Salary Per Month Variable

  • How many payments are made per year towards rent/utilities and how many times are these payments made?
Payments Made Variable

  • What is the monthly income from the state allowance?
Allowance Variable

  • What’s the minimum the family wants to spend on fun activities each month?
Fun Variable

Confident that the pre-configured model can be adjusted to fit her specific use case, Jules writes the data she has in a .dat file inside Optilogic.

Data File Image

Since the above model was built as an abstract model where the data is separated from the model itself, Jules knows that every time she wants to re-run her model (for her family or her even for her friends’ budget), she can simply swap the data out.

Data swap image

It takes less than a second for Jules to see the solution on the command line:

Command Line Results image

The Results

OptiSolver takes less than a second to solve the instance created by the given data. It takes 16 iterations to reach the optimal solution of the above linear program. Because Jules knows this is a fairly simple model, she feels confident in using the in-built solver. As her modeling gets more complex, however, she knows she’ll be able to leverage commercial grade solvers such as Gurobi, soon to be integrated into Optilogic.

MonthLeisure Money BudgetMoney Saved


































Jules explains to her family that the maximum amount of money they can spend for fun during the year is $3,550. This is wonderful news to the entire Carson family, since they now have the confidence in their finances to know that they can afford a nice family road trip vacation while securing $5,795 in the Carson family savings account over the course of 2021. Now all that’s left to do for the Carson family is to pick a road trip destination and to let Jules have the first go at the family RV’s aux cord.