My math teacher once told me that the shortest path between 2 points is a straight line, but only when both points are exactly facing each other.
2 years ago, we had a major deployment planned. Not only were we upgrading the whole application, we also had to process and migrate billions of records in a very short time frame. As a B2B company, our SLA allowed to interrupt the service between Saturday 2PM and Sunday 9PM CET.
2 days before launch, we tested the migration on 100 million entries. We had a problem: with a linear time / records ratio, the sole migration process would take more than 30 hours.
– The management is in panic. Do you have a plan B?
– So what the hell are you doing?
– We’re testing it.
– OK. What about a plan C? – Lol.
4 hours later, it was clear Plan B went beyond expectations. It was 30% faster than Plan A and allowed error recovery without replaying the whole migration.
Let’s say you need to cross a whole country in a very limited time. That country is crossed by a long, straight road from north to south. The most obvious plan is to rent a car, load enough fuel for the trip – there are no gas stations on the way – and drive until you reach your point since there’s no hotel on the road.
This is The Plan. The Plan is often the most obvious way to achieve things. The Plan tries to avoid risks by relying on simplicity.
The Plan always work in theory. But what if the motor breaks during the trip? You’ll have to wait for someone to help you or start over. What if the road is cut by a flood, or roamed by a group of pirates?
In real life, the shortest path between 2 points is not always a straight line. The straight line leaves no room for the unexpected. The straight line is The Plan.
The Plan may be great, but having a look at Plan B might be worth it. After studying plan B, you’ll see The Plan from a totally different point of view. That’s where you start seeing The Plan’s flaws and dangers.
What if you cross the whole country by plane, zig zagging from one town to another? You’ll have to consider maybe half a dozen stops and a much greater distance than expected. You’ll have to ensure your next flight exists and won’t leave you waiting for too long. You’ll probably have to travel using many transport companies, think about luggage transfer.
This is Plan B. It’s slightly more complicated than The Plan, but in the end, it’s safer. Traveling by plane is faster than by car. If a plane has a technical problem, you can still hop in the next one instead of being stuck or starting over. No need to carry your fuel, that’s the airplane company’s job.
The main problem with your Plan B: it’s more complex and more complicated to elaborate than The Plan because it steps back from the obvious. It is also more demanding in terms of resources because it needs to study a problem from various angles. But with a greater effort come more security, shorter steps and more room for the unexpected.
So every time The Plan seems the obvious one, look for a Plan B. There are chances Plan B is the plan you’re looking for.