If you always go out on date night around 6:00 pm every Saturday night you’re your wife like I do, then it’s assumed that you’ll go out this coming Saturday night, right? And the next one, and the next one, and so on…
Project assumptions work the same way. For planning purposes, you presume the event or thing you’ve made the assumptions about is true, real, or certain. For example, you might assume that key resources will be available when needed on the project. Document that assumption (always, always document!). If your tech lead is the one and only resource who can perform a specific task at a certain point in the project, document your assumption that the particular tech lead will be available and run it by his manager. If your tech lead happens to be on a plane for New York to work on tasks on a different project at the time you thought he was going to be working on the project, then you likely will have a very real – and big – problem to face. And maybe even an angry or frustrated customer.
Various assumptions we tend to make
Other assumptions could be things such as vendor delivery times, product availability, contractor availability, the accuracy of the project plan, the assumption that key project members will perform adequately, contract signing dates, project start dates, and project phase start dates. This is not an exhaustive list but should get you thinking in the right direction. As you interview your stakeholders, ask them about their assumptions and document them. Use brainstorming exercises with your team and other project participants to come up with additional assumptions. And document, document, document.
Try to validate your assumptions whenever possible. When discussing assumptions with vendors, make them put it in writing. In fact, if the services or goods you’re expecting to be delivered by your suppliers are critical to the project, include a clause in the contract to assure a contingency plan in case they fail to perform. For example, if you’re expecting 200 PCs to be delivered, configured, and installed by a certain date, require the vendor to pay the cost of rental equipment in the event they can’t deliver on the promised due date. Let the failing organization cover the budget impact you’re going to experience – don’t take the hit on your own.
Remember, when assumptions are incorrect or not documented, it could cause problems halfway through the project and might even be a project killer.