This is a question I heard often from my parents, and it was clear that they didn’t really want an answer, long before I understood the concept of a rhetorical question. As a project manager, however, this is a question that deserves considerable thought.
Much of the focus of project management is given to those work packages that fall on the critical path and how to best manage them to deliver the project on schedule. This is how it should be, but what about those work packages that do not lie on the critical path, those that have lots of float, those that can be done almost anytime during the project? Should those be done as soon as possible or put off until a later time?
In my mind, there are three good reasons for delaying the start of a work package – impact on performance, cost, and time.
Performance – Even though a work package may have no predecessors, consider if delaying the start might result in a higher quality deliverable. This is often the case when working with technology that is rapidly evolving or when the deliverable has a limited shelf life. Waiting until a later point in the project to execute the work package might allow incorporating a fresher or upgraded product, as long as it doesn’t impact the start date of dependent work packages.
It doesn’t make sense to get to the end of the project only to discover that the technology you purchased early needs to be upgraded or the products (such as adhesives or food) that you purchased and prepared weeks ago have passed their expiration date.
Cost – Work packages that have high cost deliverables might also be good candidates for putting off until tomorrow. Buying expensive materials early in a project before they are needed can skew your cost performance metrics (such as Earned Value Analysis) by spending money on items that you won’t receive value from until later. If these materials are subject to market fluctuations (such as precious metals) you can also look for an opportunity to save money by placing the order when the price is low.
In addition, should the project be cancelled before completion, buying early creates additional inventory which must be returned or dispositioned. Just be sure to consider ordering lead times and delivery delays when calculating your late start/late finish dates.
时间 – The start of implementing a project often generates a flurry of activity. Often there are key critical path work packages that must begin right away to enable on-time project completion as well as many non-critical path work packages that could be started. When these work packages require using the same resources (including people, facilities, equipment, and materials), any non-critical path work packages can pull resources and focus away from the critical path. Even if these work packages do not share resources, they can draw the attention of the project manager away from where it is most needed. Delaying the start of these work packages by even a few days can reduce the load on the project manager and team. Having a successful start to the project is key to having a successful project.
If we now agree that there are reasons to “put off until tomorrow what you can do today”, be careful to not go to the other extreme and put off everything until the last minute. Doing so removes the float from every work package and, by definition, they all become critical paths. As project manager, it is your job to be sure the work packages are starting and finishing at the optimum time for project success and not at the convenience of the work package owner.