Conwip stands for "Constant Work In Progress" and it's an approach to work management. It's used by some companies to manage how much work they are doing at once and make sure that things are done in a timely way.
Basically, with conwip, the company sets a limit for how much work can be going on at once. The company can then manage their resources (like people and equipment) to make sure that all the work gets done in a timely way, without taking on too much work at once.