予定だ => plan to, intend to N4
... 前に => Before ... N4
Relationship before and after
が必要 => need; necessary N4
... 前に => ... in front of, before N4
Relationship before and after
前に => before; in front of ~ N5
必要がある => Need/Need to N4
を前提に => On the premise of N1
Premise
手前 => considering; before; in front of; one’s standpoint N1
[事「こと」]だ => A is necessary/good (offering advice/suggestion) N3
Needs, Requirement
事と次第によって => Depending on the progress of the situation N2
How to say the beginning
~[前「まえ」]に => Before N/Vる(occurs/happens) N5
Time
[要「よう」]するに => A. In short/put simply, B N2
Adjectival, Descriptions