A surgical apparatus, comprising: a handle module comprising an attachment portion, wherein a detachable shaft module (1, 2, 3) is attachable to the attachment portion for collectively performing a surgical procedure, and wherein the handle module comprises: a rotary drive system (20, 40) for driving the detachable shaft module (1, 2, 3); an electric motor coupled to the rotary drive system for powering the rotary drive system (20, 40); one or more sensors (2144, 2146, 2148); and a handle module processor circuit in communication with the one or more sensors (2144, 2146, 2148) and the electric motor, wherein the handle module processor circuit is programmed to: control the electric motor; track an end-of-life parameter for the handle module based on input from the one or more sensors (2144, 2146, 2148); and maintain a count of the end-of-life parameter, wherein the surgical apparatus further comprises means, in communication with the handle module processor circuit, for taking an end-of-life action when the handle module processor circuit determines that the count for the end-of-life parameter reaches a threshold value, characterised in that the means for taking the end-of-life action comprises means for disabling the handle module for a subsequent surgical procedure, and wherein the means for disabling the handle module comprise means (1002, 1012, 1040) for preventing installation of a charged battery pack in the handle module. a handle module comprising an attachment portion, wherein a detachable shaft module (1, 2, 3) is attachable to the attachment portion for collectively performing a surgical procedure, and wherein the handle module comprises: a rotary drive system (20, 40) for driving the detachable shaft module (1, 2, 3); an electric motor coupled to the rotary drive system for powering the rotary drive system (20, 40); one or more sensors (2144, 2146, 2148); and a handle module processor circuit in communication with the one or more sensors (2144, 2146, 2148) and the electric motor, wherein the handle module processor circuit is programmed to: control the electric motor; track an end-of-life parameter for the handle module based on input from the one or more sensors (2144, 2146, 2148); and maintain a count of the end-of-life parameter, a rotary drive system (20, 40) for driving the detachable shaft module (1, 2, 3); an electric motor coupled to the rotary drive system for powering the rotary drive system (20, 40); one or more sensors (2144, 2146, 2148); and a handle module processor circuit in communication with the one or more sensors (2144, 2146, 2148) and the electric motor, wherein the handle module processor circuit is programmed to: control the electric motor; track an end-of-life parameter for the handle module based on input from the one or more sensors (2144, 2146, 2148); and maintain a count of the end-of-life parameter, control the electric motor; track an end-of-life parameter for the handle module based on input from the one or more sensors (2144, 2146, 2148); and maintain a count of the end-of-life parameter, wherein the surgical apparatus further comprises means, in communication with the handle module processor circuit, for taking an end-of-life action when the handle module processor circuit determines that the count for the end-of-life parameter reaches a threshold value, characterised in that the means for taking the end-of-life action comprises means for disabling the handle module for a subsequent surgical procedure, and wherein the means for disabling the handle module comprise means (1002, 1012, 1040) for preventing installation of a charged battery pack in the handle module.