Perimeter Action Ships are part of a unique military strategy used against both the Klingons and Romulan during many of the early conflicts. Perimeter Action Ships were designed to use stealth and heavy firepower to engage enemy vessels during times of war.
Most Perimeter Action Ships do not have the extensive crew facilities found on other Destroyer vessels, often being on patrol for no more than 6 months. Perimeter Action Ships are smaller than a standard Destroyer, but have similar mass. Perimeter Action Ships use even more specialized and stealthy sensor systems, and are designed to be mass produced easily. Most Perimeter Action Ships do not have the research capability of a Destroyer, and rarely have shuttle bays, extensive repair facilities or emergency systems. Perimeter Action Ships do mount a large number of redundant systems, giving them more resilience in battle.
Although easy to mass produce, Perimeter Action Ships are surprisingly expensive, often costing twice what a standard Destroyer costs. This, coupled with their limited exploration capability has kept their numbers reduced. But their heavy firepower and other unique systems continue to create a niche not filled by a standard Destroyer.