FIRE Archives - Page 4 of 11

Twenty Years of Models, One at a Time

I’ve been doing operations research for over 20 years. Most of what I’ve built is locked inside Excel files on a hard drive. Not because Excel is where OR models belong — it isn’t, really — but because that’s where the data was, that’s where the clients were, and that’s what worked at the time.

The backlog is real. Staff scheduling, vehicle routing, warehouse slotting, least-cost formulation, a few others. Each one took months to build and calibrate. Each one is doing nothing right now except existing as a .xlsm file.

Excel optimization models waiting to be converted into web apps

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The $2M Project That Died in a Pandemic (And What I Did With the Code)

A few years ago I helped build a truck routing system for a logistics company. It was a real project — real trucks, real delivery stops, real time windows, real money. The client spent around $2 million on it. Then the pandemic hit. The project died. And the code sat on my hard drive doing nothing.

Last week I turned it into a web app.

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What’s Next: 20 More Models Waiting in Excel

The staff scheduler took about 20 years to build.

That’s not as dramatic as it sounds. The MILP model — the math, the constraints, the logic — that came together during the Fiverr engagement described in the first post of this series. What took 20 years was accumulating enough Operations Research experience to know what the model needed to look like. The actual build, once I sat down with the problem fully understood, was fast.

The web app took a few days. The deployment took an afternoon, plus one failed attempt that taught me about gunicorn.

The Client Who Changed His Mind (And Why I Finished the Job Anyway)

Years ago, I was doing gigs on Fiverr. Mostly Excel work — macros, pivot tables, solver models. I had a profile and a handful of listings, and I’d written about that whole love/hate experience back in 2017 (short version: the clients who treat you like a vending machine are the price you pay for the ones who bring you genuinely interesting problems). One day, a genuinely interesting problem showed up.

A training company needed help scheduling their staff. Multiple clients, multiple courses, multiple instructors, limited hours, shared equipment, weird simultaneous constraints. Classic Operations Research territory. I said yes.

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The Best Time to Convert a 401(k) to a Roth IRA

If you’re asking what the best time to convert a 401(k) to a Roth IRA is, here’s the short answer: it’s not a date on the calendar, it’s a low-income year. A conversion is taxed at your marginal rate the year you do it, so the entire game is converting when that rate is as low as it will ever be. Get the timing right and you move money to the tax-free side cheaply; get it wrong and you hand the IRS more than you needed to.