Accurately Estimating Your Project Plan

January 31, 2024


On-the-job mistakes can be expensive. Think about the expense that is incurred when a critical piece of functionality is left out of a project. It may be a requirement that was missed or a design flaw that was discovered later in the development cycle.

The team now has to scramble and undo what was done and redesign the solution to incorporate the new understanding. Then the team can begin moving forward again.

Regardless of the reason, these types of oversights can be very expensive. You not only lose the time that you went down the wrong path, but you also have to backtrack and then go down a new path as well.

This quickly adds up to real dollars and can even take a toll on the team’s morale.

No matter how big of a mistake you may have made, there are few that are as astronomical as the mistake that occurred with the Hubble telescope.

This project was 15+ years in the making and somewhere in the neighborhood of 3 billion dollars. In April 1990 the telescope went into orbit.

The first images started coming back and it was immediately obvious that something had gone wrong. Rather than sharp and high-definition images coming back to the earth, the images were coming back blurry!

Something had gone horribly wrong. It was discovered that Hubble had fallen victim to a flaw called “spherical aberration”.

There was an extremely tiny mistake in the shape of the lens that caused the light to not reflect properly. This resulted in blurred images and extreme disappointment from all who worked on the project. Fortunately, we all know they were able to fix the problem and breathtaking images started flooding back to Earth.

Most project managers don’t deal with that type of high visibility and high-budget projects. But, in the context of our organizations, we do have Hubble-like projects.

Projects that everyone is banking on to save the day, bring in more revenue, or make a client extremely happy. It’s important to not knowingly make mistakes on these projects. Part of preventing that from happening can be realized by accurately estimating your project plan.

The Importance of Accurately Estimating Your Project Plan

The VP of Marketing gets on the elevator with you. They know you recently received a request for a project to be completed for their department.

After a few seconds of chit-chat, the VP goes right for the project manager’s jugular. “So…” he says and then pauses ever so slightly before he continues. “How long do you think this project is going to take to complete?”

That’s an innocent enough question, isn’t it? You’ve been able to spend a few minutes reviewing the project plan. It’s not even close to being complete, but you feel a compelling need to open your mouth and respond.

Don’t do it! It’s a trap! WARNING, WARNING, WARNING. Don’t fall for his wily ways.

The date is etched in stone the moment you open your mouth and say “oh, I think that can be done by the end of the month. But, it depends on a lot of things like the final scope of the project, the resources available, and other priorities that may get in the way.

So, there’s no guarantee at this point.” Do you know what the VP heard? “We’ll get this done by the end of the month.”
Then, he takes those winsome words and adds his own spin to them. “Yeah, I talked to the project manager today.

He promises to have it done by the end of the month and may even be able to pull the date up a bit.” You haven’t even had the chance to really dig into the project plan and here you are promising to get it done in less than 30 days!

3 Tips for Accurately Estimating Your Project Plan

What can you say to someone who corners you in the elevator and asks how long something is going to take when you are not ready to give that information? Keep these tips in mind to help you navigate that tricky conversation:

  • Develop an Aversion to Baseball

Who doesn’t like baseball? We’re not actually talking about developing an aversion to baseball, but more specifically to the baseball park. Stay away from ballpark estimates as much as possible.

It’s easy to throw a number over the fence for the purpose of getting someone off your back and giving them the information they think they want. Resist this urge. Until you have a fully developed project plan it’s hard to provide an accurate estimate.

This is the land where mistakes are bred. A date gets thrown out to an influential VP in the company and you now “own” that date. Once you’ve had a chance to fully vet the project plan you find out that there’s no way that date can be met.

You look for every opportunity to shorten the length of the project by either fast-tracking or crashing the schedule. This gets you closer to the date but leaves you zero margin for error and causes people to have to rush through their tasks.

Stay away from the ballparks. Spend as much time as necessary putting the project plan together and then locking down a date that is real.

  • Ask for Something in Writing

Another tip to help you accurately estimate your project plan is to get something in writing. Someone comes to you and says they have a great idea for a new project.

It’s going to do this, save that, and make a huge difference to the bottom line. They want to know if you think it’s possible from your perspective.

First, you want to reiterate your disdain for ballparks, but for the sake of your professional relationship (it may be a peer or colleague that you have a lot of respect for), you’ll put something together.

However, they need to do something first. Provide you with a high-level outline of what they want to accomplish in writing. They can send you a quick email to this effect. You can then base a loose estimate on these facts, and at the same time have a reference to the original scope of the project.

Something else may occur in this situation as well. You may not even receive the email. It may not be important enough for this person to follow through on. If so, you just saved yourself some time and prevented the possibility of throwing out an inaccurate estimate.

  • Keep It Accurate

Some may feel that the way to provide estimates is to double what you think it will take and then double it again. This ends up with ridiculously large and unreasonable project plan estimates. This has two negative consequences.

It could potentially cause work that your company could do to be turned down for being too expensive. Or, it could also have the effect of being approved at an inflated budget which could take the budget away from another relevant project your company needs to complete. Either way, it’s not a good habit to get into when you want to keep your estimates as accurate as possible.

Very few project managers will have a day as bad as those at NASA when they realized what was wrong with their telescope. But, you can still have a pretty bad day nonetheless if something goes wrong on your projects.

Take the time upfront to carefully and precisely estimate your projects. You’ll save yourself and your team a lot of time and prevent a lot of headaches by doing so!

Gulit Upadhyay


This article was provided by Gulit Upadhyay, Sr. Digital Marketer at, a company dedicated to providing Solar and EPC project management software so that you can achieve business excellence.