It's a custom developed planning/forecasting tool. It's a P x Q thing, but the P and Q are variable as to the type and mix of the Ps and Qs and need to be combined/sliced into many different ways for analysis/planning/forecasting. The team actually developing it has been very challenged.
You're not really challenged until the growth rate of their Excel monster outpaces the rate at which you automate the existing stuff... thankfully Excel has a 1 million row limit, and it always takes them time to figure out how to shard an Excel database :P
Well in this case it's actually mine and the rest of the finance group's Excel monsters (plural) that are being automated. The devs are doing yeoman's work.