A method for verifying the operability of a safety valve (310; 410; 510; 610; 710); 1.1 wherein the safety valve (310; 410; 510; 610; 710) comprises 1.1.1 a valve member and 1.1.2 a positioner (340; 440; 540; 640; 740) for controlling the position of the valve member; 1.2 wherein the safety valve (310; 410; 510; 610; 710) is part of a plant on which a process with a process medium runs; 1.3 wherein the plant comprises at least one sensor (350; 450; 550; 650) for monitoring the state or a property of the plant and/or the process and/or the process medium; 1.4 wherein the method comprises a first partial stroke test and a second partial stroke test for verifying the operability of the safety valve (310; 410; 510; 610; 710); 1.4.1 wherein for the first partial stroke test a first stroke of the valve member is predetermined by the positioner (340; 440; 540; 640; 740); wherein the method comprises the following steps: 1.5 at least one measured value of at least one of the sensors (350; 450; 550; 650) is acquired; 1.6 based on at least one of the measured values, a point in time during the ongoing process is determined at which the second partial stroke test may be performed; 1.6.1 wherein the second partial stroke test has a second stroke of the valve member by the positioner (340; 440; 540; 640; 740) which is greater than the predetermined first stroke of the first partial stroke test and less than or equal to the stroke in a full stroke test; and 1.6.2 wherein the second stroke is such that the second partial stroke test can disrupt the process to no more than a predetermined extent; 1.7 wherein the second partial stroke test is performed at the predetermined point in time. 1.1 wherein the safety valve (310; 410; 510; 610; 710) comprises 1.1.1 a valve member and 1.1.2 a positioner (340; 440; 540; 640; 740) for controlling the position of the valve member; 1.1.1 a valve member and 1.1.2 a positioner (340; 440; 540; 640; 740) for controlling the position of the valve member; 1.2 wherein the safety valve (310; 410; 510; 610; 710) is part of a plant on which a process with a process medium runs; 1.3 wherein the plant comprises at least one sensor (350; 450; 550; 650) for monitoring the state or a property of the plant and/or the process and/or the process medium; 1.4 wherein the method comprises a first partial stroke test and a second partial stroke test for verifying the operability of the safety valve (310; 410; 510; 610; 710); 1.4.1 wherein for the first partial stroke test a first stroke of the valve member is predetermined by the positioner (340; 440; 540; 640; 740); wherein the method comprises the following steps: 1.4.1 wherein for the first partial stroke test a first stroke of the valve member is predetermined by the positioner (340; 440; 540; 640; 740); wherein the method comprises the following steps: 1.5 at least one measured value of at least one of the sensors (350; 450; 550; 650) is acquired; 1.6 based on at least one of the measured values, a point in time during the ongoing process is determined at which the second partial stroke test may be performed; 1.6.1 wherein the second partial stroke test has a second stroke of the valve member by the positioner (340; 440; 540; 640; 740) which is greater than the predetermined first stroke of the first partial stroke test and less than or equal to the stroke in a full stroke test; and 1.6.2 wherein the second stroke is such that the second partial stroke test can disrupt the process to no more than a predetermined extent; 1.6.1 wherein the second partial stroke test has a second stroke of the valve member by the positioner (340; 440; 540; 640; 740) which is greater than the predetermined first stroke of the first partial stroke test and less than or equal to the stroke in a full stroke test; and 1.6.2 wherein the second stroke is such that the second partial stroke test can disrupt the process to no more than a predetermined extent; 1.7 wherein the second partial stroke test is performed at the predetermined point in time.