How best to model project completion by adjusting available resources?

Question

I'm PMing our team of 4 engineers (myself included) but am pretty new to process. In attempting to plan out our work for the next year (and we have lots) I'm looking for the right way to:

• List projects (essentially buckets of work) with expected cost in person-days
• List available engineers (resources)
• Set deadlines on some projects
• Set priorities on projects

One of the key things I'm hoping to achieve is to use the above to assign work to engineers and figure out our hiring needs. I'm imagining something like a slider where I can increase or reduce available engineers to model when projects can be completed, potentially highlighting those with deadlines that won't make it in time.

I'm currently attempting to use Excel/Google Sheets with some formulae, but I'm not quite sure how to handle the "modeling" part. Any help/pointers are appreciated.

Answer 1

Your modeling approach appears to be too simplistic

You did say that you are new to process, so it is understandable :)

• You seem to be assuming that any engineer can do any project: This is rarely the case. There will be specific skill requirements for specific projects that precludes you from doing that.

• You seem to be trying to model schedule, which is much harder than modeling workload: For example, let us say you only have enough workload for 4 engineers. And yet you may have hot spots where you will miss deadlines, while at other times you may have idle engineers. Hiring more engineers will reduce the hot spots, but you will also increase overall idle time.

On the positive side:

• You seem to have full visibility into the workload and deadlines for the entire year (Are you not going to accept any new work during the year?)

• You seem to have effort estimates for the work (How reliable are these?)

I would go about modeling it like this

1. Take the overall workload for the year and divide it by the hours available per engineer: This will give you an initial headcount number. If this shows a shortfall of engineers, you can make firm hiring decisions on this number right away. Even if the schedules are totally flexible you need this additional headcount to handle the extra workload.

2. Do a detailed schedule for the first quarter: If you find hotspots, see what flexibility you have in the contracts to even out the workload. After trying to even the workload, if you still find you need additional staffing, you will have to make the hard decision of hiring additional engineers knowing that you are increasing idle time.

3. Do a similar analysis for the second, third and fourth quarters well in advance of that quarter: However, this has to be done for each quarter early enough to give adequate lead time to hire/induct/train them.