The strategic plans and assessments of each alliance changed dramatically over the course of the Cold War as plans, philosophies, and resource commitments changed. Please specify a particular timeframe for a more detailed answer.
In general, the Warsaw Pact enjoyed a substantial superiority in conventional forces over NATO in Central Europe throughout the Cold War, and Soviet strategic planning called for always stationing what they believed was sufficient forces in the theater to break the western alliance without using nuclear weapons.
In contrast, NATO didn't really take conventional forces seriously for quite some time. Policy called for conventional forces to basically act as a tripwire and trigger strategic nuclear response. It wasn't until the 60s that policy began to change in that front, and a credible conventional deterrent didn't really exist until the late 70s at the absolute earliest. IMO it really wasn't until the 80s and the electronic revolution that NATO's qualitative advantage gave it a legitimate chance to defeat a WP invasion without nuclear weapons.
Just as a sort of overall strategy, Pact plans always centered around an offensive into West Germany, while NATO plans were entirely defensive in nature.
Happy to give more details for specific eras.