>If the old code has 104 weeks worth of features, and the maintenance team works on fixes and additions for 1 day per week ... you'll need 130 weeks to catch up

>If the old code has 104 weeks worth of features, and the maintenance team works on fixes and additions for 1 day per week ... you'll need 130 weeks to catch up. I don't agree with this as a general rule. All the communication, specification and validation of the features is already done in the old system and can be reused, the actual implementation didn't take 104 weeks in the old system and should take even less in the new.