Agile has his concept of "horizon of predictability". Basically, you are semi-accurate within the two-week range. After that, the accuracy nosedives. At 6 month

Agile has his concept of "horizon of predictability". Basically, you are semi-accurate within the two-week range. After that, the accuracy nosedives. At 6 months, you could be off by, well, 6 months.