In this article we are going to present a general procedure for inserting a time conformal factor in the general plane symmetric static spacetime, to it non static. The gravitational waves are plane symmetric and non static, therefore this development will help to understand the phenomenon of formation of gravitational waves. We know that the gravitational waves decay with the passage of time. Its mass-energy momentum tensor must depends on time. To get a time dependent mass-energy momentum tensor we have to insert a time dependent conformal factor in plane symmetric static spacetime. For this purpose we use the Noether symmetry equation and obtain a particular time dependent conformal factor without losing the plane symmetry of the said spacetime. We define a theorem in this regard, which will works for all general plane symmetric distributions.