An insertion system, the insertion system comprising: a base adapted to be carried by a patient; a first device housing configured to be operatively engaged with and disengaged from the base, the first device housing comprising: a first carrier body arranged for movement within at least a portion of the first device housing at least between a retracted position and an advanced position, the first carrier body for supporting a piercing member in a position orientated for insertion through skin of the patient upon movement of the first carrier body from the retracted position to the advanced position; and a second device housing configured to be operatively engaged with and disengaged from the first device housing, the second device housing comprising: a second carrier body arranged for movement linearly within at least a portion of the second device housing at least between a retracted position and an advanced position, the second carrier body operatively engageable with the first carrier body; a drive mechanism comprising a torsion spring member arranged within the second device housing; a cam assembly rotatable at least between a first orientation and a second orientation; the cam assembly configured to move the second carrier body toward the advanced position as the cam assembly rotates from the second orientation to the first orientation; the cam assembly configured to move the second carrier body toward the retracted position as the cam assembly rotates from the first orientation to the second orientation; wherein the drive mechanism is arranged to provide a rotational force to the cam assembly such that the second carrier body is caused to move from the retracted position to the advanced position; movement of the second carrier body from the retracted position to the advanced position further causing the first carrier body to move from the retracted position to the advanced position so as to insert at least a portion of the piercing member (446, 448) through skin of the patient; and wherein the line traveled by the second carrier body and the line traveled by the first carrier body share a common axis. a base adapted to be carried by a patient; a first device housing configured to be operatively engaged with and disengaged from the base, the first device housing comprising: a first carrier body arranged for movement within at least a portion of the first device housing at least between a retracted position and an advanced position, the first carrier body for supporting a piercing member in a position orientated for insertion through skin of the patient upon movement of the first carrier body from the retracted position to the advanced position; and a first carrier body arranged for movement within at least a portion of the first device housing at least between a retracted position and an advanced position, the first carrier body for supporting a piercing member in a position orientated for insertion through skin of the patient upon movement of the first carrier body from the retracted position to the advanced position; and a second device housing configured to be operatively engaged with and disengaged from the first device housing, the second device housing comprising: a second carrier body arranged for movement linearly within at least a portion of the second device housing at least between a retracted position and an advanced position, the second carrier body operatively engageable with the first carrier body; a second carrier body arranged for movement linearly within at least a portion of the second device housing at least between a retracted position and an advanced position, the second carrier body operatively engageable with the first carrier body; a drive mechanism comprising a torsion spring member arranged within the second device housing; a cam assembly rotatable at least between a first orientation and a second orientation; the cam assembly configured to move the second carrier body toward the advanced position as the cam assembly rotates from the second orientation to the first orientation; the cam assembly configured to move the second carrier body toward the retracted position as the cam assembly rotates from the first orientation to the second orientation; wherein the drive mechanism is arranged to provide a rotational force to the cam assembly such that the second carrier body is caused to move from the retracted position to the advanced position; movement of the second carrier body from the retracted position to the advanced position further causing the first carrier body to move from the retracted position to the advanced position so as to insert at least a portion of the piercing member (446, 448) through skin of the patient; and wherein the line traveled by the second carrier body and the line traveled by the first carrier body share a common axis.