The Old Resource Switch Trick

I want to start this posting by saying: a) I don’t think vendors are evil b) I don’t think my simple tools are better then MS Project or other Professional ones

I have been on a number of projects, where during the sales process, followed by all efforts to estimate, my vendor will suddenly re-assign the fully qualified resource I have been working with to another project and give me someone ‘who is just as good’. I have also had this happen with internal departments, such as internal development groups. Either way, I consider this deceptive and a significant impact to the project schedule (and yes, I am assuming here the resource is not as qualified as the original). Why? Because vendors often use their more impressive resources to make the sale or get the project moving, but then require those resources to perform that same magic elsewhere.

Why assume that the newly assigned resource is not as good? Firstly, why would resource X be removed in the first place if resource Z is just as good? It is possible there is a legitimate reason, but mainly I think it is not the case. If you are working well and already trust that resource, it is in the vendor’s interest to keep the client happy. Secondly, the person now doing the work is no longer the person who made the estimates. That is always less desirable. To be fair, sometimes it is the customer (in this case myself or you as the PM) who requests a new resource. This could be because of quality issues (maybe you will get someone better), cultural issues (of the organizational kind) or something else. Regardless of who removes the original resource, your estimates and costs are now in question.
Here is a quick analysis tool I made in excel to help you size up the risk that was just created:

You have three questions to answer, per work package that is impacted by the resource change:
1. What is the qualification of the new resource (assume 100% for the original)?
2. What is the availability of the new resource (assume 100% for the original, unless you know otherwise)?
3. What is the rate of the new resource (again, I am assuming you knew the rate of the old resource)? Enter this information in the correct fields and you will now know your new duration and cost for that work package.

How it works:
Duration = (effort/qualification)/availability
Where effort is an hours value and both qualification and availability are % values

Cost= effort/qualification*rate
Where effort is an hours value, qualification is a % value and rate is a currency value You do need to know your original estimates as well.

You do this for two rows, row 1 is the original resource and row two is the new resource, this way you have a clear indication of the change if you don’t feel like computing the DELTA elsewhere.

Obviously you can do all of this in MS Project (and in more holistic way), but sometimes you need a quick and dirty picture that is easy for your stakeholders to grasp.
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Please email me for the calculator in excel format.