An operation management device for high-frequency resistance welding and induction welding, which performs an operation management for high-frequency resistance welding or induction welding in which a strip-shaped metal plate is formed to have a cylindrical shape in such a manner that both end portions of the metal plate gradually face each other while the metal plate is conveyed, and a Vee convergence section that is a portion at which both of the end portions butt against each other while facing each other is welded, the device comprising: an imaging device is disposed above the metal plate to capture a self-luminescent pattern in an area including the Vee convergence section of the metal plate, an input unit, wherein image data imaged by the imaging device is input to the input unit, characterised by: a measuring unit that measures a distance L [mm] between a first Vee convergence point at which both of the end portions of the metal plate geometrically come into contact with each other and a second Vee convergence point that is a contact point of both of the end portions of the metal plate, and a Vee convergence angle θ[°] at the first Vee convergence point based on an image of an area including the Vee convergence section; and a determining unit that determines whether or not the distance L [mm] and the Vee convergence angle θ[°] satisfy the following equation: L min θ / θ st − 0.15 ≤ L ≤ 35 wherein L min [mm]: Reference distance that is set in advance θ st [°]: Reference angle that is set in advance; wherein the measuring unit includes: a first detecting unit that binarizes the image to generate a binary image, determines both of the end portions of the metal plate from the binary image, linearly approximates both of the end portions of the metal plate within a predetermined range in a closed direction of a formed V-shape to generate two approximated straight-lines, and detects an intersection point of the approximated straight-lines as the first Vee convergence point, and a second detecting unit that binarizes the image to generate a binary image, and detects the second Vee convergence point from the binary image. an imaging device is disposed above the metal plate to capture a self-luminescent pattern in an area including the Vee convergence section of the metal plate, an input unit, wherein image data imaged by the imaging device is input to the input unit, characterised by: a measuring unit that measures a distance L [mm] between a first Vee convergence point at which both of the end portions of the metal plate geometrically come into contact with each other and a second Vee convergence point that is a contact point of both of the end portions of the metal plate, and a Vee convergence angle θ[°] at the first Vee convergence point based on an image of an area including the Vee convergence section; and a determining unit that determines whether or not the distance L [mm] and the Vee convergence angle θ[°] satisfy the following equation: L min θ / θ st − 0.15 ≤ L ≤ 35 wherein L min [mm]: Reference distance that is set in advance θ st [°]: Reference angle that is set in advance; wherein the measuring unit includes: a first detecting unit that binarizes the image to generate a binary image, determines both of the end portions of the metal plate from the binary image, linearly approximates both of the end portions of the metal plate within a predetermined range in a closed direction of a formed V-shape to generate two approximated straight-lines, and detects an intersection point of the approximated straight-lines as the first Vee convergence point, and a second detecting unit that binarizes the image to generate a binary image, and detects the second Vee convergence point from the binary image. a measuring unit that measures a distance L [mm] between a first Vee convergence point at which both of the end portions of the metal plate geometrically come into contact with each other and a second Vee convergence point that is a contact point of both of the end portions of the metal plate, and a Vee convergence angle θ[°] at the first Vee convergence point based on an image of an area including the Vee convergence section; and a determining unit that determines whether or not the distance L [mm] and the Vee convergence angle θ[°] satisfy the following equation: L min θ / θ st − 0.15 ≤ L ≤ 35 wherein L min [mm]: Reference distance that is set in advance θ st [°]: Reference angle that is set in advance; L min [mm]: Reference distance that is set in advance θ st [°]: Reference angle that is set in advance; a first detecting unit that binarizes the image to generate a binary image, determines both of the end portions of the metal plate from the binary image, linearly approximates both of the end portions of the metal plate within a predetermined range in a closed direction of a formed V-shape to generate two approximated straight-lines, and detects an intersection point of the approximated straight-lines as the first Vee convergence point, and a second detecting unit that binarizes the image to generate a binary image, and detects the second Vee convergence point from the binary image.