The integral pom-pom model is analyzed through the non-equilibrium thermodynamical framework GENERIC. The integral expression for the orientation tensor is after extension of the state space with contour label s reformulated into the equivalent Fokker-Planck equation for the tube surrounding the crossbar and withdrawn arm segments. The extra stress tensor is reproduced but the independent alignment approximation (IAA) is avoided through the irreversible dynamics for the contour length stretching, which is justified from its entropy production rate. Based on the GENERIC formalism the dissipative part of contour length stretching is adjusted to guarantee that the stretch variable is always positive.