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"What If” Scenarios with MS Project

Every software development project I’ve ever been involved with has changed over the course of its life cycle. Change is the only constant a project manager can rely on. If you’re managing a project where no one asks for change, your project has ceased to matter and no one has told you. Software development projects change for many valid reasons that include changing market places, changing budgets, and changing minds. Managing a software development project requires us to be diligent managers of change. One of the first steps in managing change is to estimate the cost and time required to make the change. Cost estimation is fairly straight forward: you simply have an SME estimate the cost of the new work, identify any existing planned work that would be eliminated, subtract the cost of the eliminated work from the cost of the new work and there’s your cost estimation. Estimating the change to the schedule will be much more difficult but there are tricks that you can use to simplify this analysis.


Your MS Project file is the tool that takes the kinks out of what can be a complex analysis. It’s a safe bet that if your project is large and complex enough to require a tool such as MS Project to manage your schedule, calculating the impact a requested change would have on the schedule will be very difficult to determine without help and this is where the tool will bail you out. Use the MS Project file to create a new baseline (MS Project 2007 allows you to create up to 11 of them), or simply rename the file as though you were using the existing file for a new project. Now update the new baseline or file with the requested change, not forgetting to delete any work that will be obsolete as a result of the change.


The change to the WBS and schedule will alter the completion date of the project unless the new and deleted activities have no successor activities dependent on them. Here’s where a little effort is required to validate the new completion date. How much effort will be required will depend somewhat on how well the work was broken down and scheduled in the first place, and what version of MS Project you use. If the final completion date hasn’t shifted at all and you know the new activities satisfy dependencies of future work, check your new MS Project file to verify that those dependencies have been defined in the file. Define them if they were missed. You can use the "Change Highlight” feature if you’re using MS Project 2007; this feature will highlight all the successor activities which have their start and finish dates changed by a change to a predecessor date. Now that you have a "what if” scenario with all the dependencies defined, check the final completion date again. It’s time for another check if the new date seems to be too far in the future. Have all the new dependencies been defined properly? Should they be finish to start or can they be finish to finish and a lag time specified? Make sure that all the dependencies make sense and activities start as soon as possible.


Check your resource scheduling to ensure that the proposed change can be accommodated with existing resources, or the new resources you’ve assigned in your "What if” scenario plan. Use the Report feature in MS Project, selecting Resource Usage, to view the work hours per week, per resource. You may need to do some load leveling should this report have a resource working more than the allowed number of hours in a given week or day.


The final step is to examine the new schedule to determine if there are different approaches to doing the work that would deliver the changed project in less time. Take care when doing this to note any risks that the project would be exposed to as a result of changing the approach to doing the work. This may feel like handing a loaded gun to your stakeholders and encouraging them to pull the trigger but if you identify any risks attendant on the new approach, and manage those risks, you may be enabling a change that will make the difference between a project that delivers a system that doesn’t meet your organization’s needs and one that does.


Now is when MS Project can be especially helpful. You have a change request that requires a decision by your Change Control Board (CCB). Let’s assume that these folks aren’t at your beck and call and a decision must wait on their availability. The delay between the time you create your new baseline or MS Project file with the proposed change and the time a decision is rendered may be several days during which time project work is being done. How do these updates get captured if the change is approved? The simplest approach is to maintain your "What if” scenario MS Project file along with your regular plan. Update both when work is reported complete or partially complete. You can then simply switch plans if the change is approved, or do nothing if it isn’t. Using the Interim Plan feature is another approach. Create an interim plan in your "What if” scenario and then track updates in the interim plan. Update the MS Project file from the interim plan should the change be approved, otherwise selectively update the MS Project plan with the actuals (or partials) from the completed (or partially completed) activities common to both plans. The interim feature makes this relatively painless.


Don’t forget that an approved change which changes the schedule will require your MS Project file to be re-baselined. If you chose this option to do your "What if” scenario, no further action is necessary. You’ll have to re-baseline the old file otherwise. From the point at which the change is approved forward you should be comparing project performance against the new baseline. I’ve made reference to several MS Project features in this article. You should refer to an MS Project manual if you aren’t familiar with these features and their use. MS Project has been designed to support all the best practices described in the PMBOK. You can learn these best practices and get your PMP certification at the same time by taking a good PMP Course or other PMP Exam Preparation training.