(from the SPI rulebook:)
"Victory in the west is a set of regiment/battalion level simulations of critical campaigns that occured on the western German frontier in the fall and winter of 1944-45."
It uses variable unit strength. Units are rated for size and morale but actual strengths (fog of war) are determined by drawing a chit randomly.
The Victory in the West system has its roots in Operation Typhoon, itself a derivation from Panzergruppe Guderian.
The Killing Ground & Iron Tide: Panzers in the Ardennes share the same system though they are both from different designers and publishers.
The series continues in the East with Fall Blau: Army Group South, June-December 1942.
Deer Valley Game Company - GAME KIT.
[Note: not to be confused with Victory in the West: Plan Yellow, The French Campaign 1940 game on France 1940]