The primary design purpose of the Sisu SA-150 for the Finnish Defence Forces was to serve as a multi-purpose, versatile military vehicle. It was primarily designed for transport and logistical support in various terrains and conditions, reflecting Finland's emphasis on mobility and durability in its defense strategy. The SA-150 was built to carry troops, equipment, and supplies, offering a robust solution for the Finnish military's needs during the Cold War era. Its design incorporated features suitable for off-road capabilities, which were crucial for operations in Finland's challenging landscapes.

For more detailed information, you can explore sources like military vehicle databases or historical records regarding Finnish military equipment.