Any engineering manager will recognize the 90/10 rule of project management, where the first 90% is completed in 10% of the time, but the last 10% is the most agonizing and will take 90% of the time. Like an iceberg where typically only one-tenth of its volume is above water, a lot of what is going on in a project is hidden from view. Careful project management makes the 90% much more visible and avoids the 90/10 rule.Why is the last 10% of the project the toughest part?Putting off the unknown until the end: In the interest of moving projects forward, we tend to overlook the areas we are unsure of and focus on what we know. It is human nature to do the easy things first and exactly the wrong thing to do. Do the difficult things first. You can predict the easy things, but you can’t predict the hard ones.Last minute changes: No matter how much you plan, there will usually be some last minute changes. Having a clear set of priorities allows you to respond to last minute changes efficiently. Do you need to optimize for schedule, tight specs or budget? Understanding the project’s flexibility allows you to handle the engineering trade-offs with last minute changes. Some last minute changes should not be done. How do you decide which changes to postpone? Look at the impact of the change and the impact of not making the change. Be sure to include everything that is affected by a change: longer schedule, more engineering time, rework or new fabrication, risk that the change will have a flaw, which can cause additional delay and cost.Over-committed resources: Often, resources are shared among multiple projects, they are over-committed, and everything suffers as a result. Typically the communication falls apart first. Team members who are shared on multiple projects are often tempted to skip team meetings and regular communication. Communication may become exclusively by email. It is critical to allow and plan for frequent communication. Email alone is not sufficient to keep everyone informed and aware of the project status.Voler Systems actively manages projects to reduce risk. We identify things that are risky or hard to do and address them first. Sometimes we recommend a feasibility phase in which we do some quick testing or evaluation to lower the risk on something that has never been done before. We set realistic deadlines and meet them by following effective project management techniques. This includes regular communication, clear and complete specifications, and a schedule and plan that is reviewed regularly.