[2] The idea for a self-propelled howitzer within the SAF was developed in the early 1990s, with the aim of providing better fire support to the armour brigades in the Combined Arms Divisions.

This new weapon system would require the ability to keep pace with the high tempo of armoured operations, while providing the range, firepower and accuracy that the artillery is renowned for.

As land in Singapore is scarce, firing tests were first done at the Waiouru Army Camp live-firing range in New Zealand as part of Exercise Thunder Warrior in February 2004.

This has been upgraded in a number of key areas and has a new power pack similar to that fitted to ST Kinetics Bionix infantry fighting vehicle (IFV), which is already in SAF service.

The use of common subsystems for the Primus and Bionix IFV offers several advantages, including easier training and reduced logistics.

The digital fire control system automates the complete projectile loading process and gun laying operation.

On 19 January 2019, Singapore Army NSman Corporal First Class (CFC (NS)) and Mediacorp Actor, Aloysius Pang was killed after he was crushed by the gun barrel of a Primus while performing maintenance inside the vehicle during his overseas reservist training in New Zealand.