roughly first
まずは大雑把に
=
roughly
first
大雑把
=
rough
まず
= first
段階的詳細化
=
gradual refinement
段階的
=
incremental
,
gradual
,
stepwise
,
step by step
詳細化
詳細
= in
detail
-化
= to make or become, -ify, -ification
from rough to detail