An operation management device performs an operation management for electric resistance 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, which is a portion at which both of the end portions butt against each other while facing each other, is welded. Furthermore, the operation management device includes: 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 on the basis of 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 (1). Lmin(θ/θst)−0.15≦L≦35  (1)