Spinal correction rod implant manufacturing process part comprising: ➢ an estimation step of a targeted spinal correction rod implant shape which is based on a patient specific spine shape correction of a patient specific spine and which includes a patient specific spine 3D modeling (91, 92), ➢ one or more simulation loops each comprising: ∘ a first simulation step of an intermediate spinal correction rod implant shape resulting from a modeling of a mechanical interaction between said patient specific spine and: ▪either, for the first simulation loop, said targeted spinal correction rod implant shape, ▪or, for subsequent simulation loop or loops, if any, an overbent spinal correction rod implant shape resulting from the previous simulation loop, ∘ a second simulation step of a spinal correction rod implant shape overbending which is applied to said targeted spinal correction rod implant shape to give a resulting overbent spinal correction rod implant shape and which is representative of a difference between: ▪either, for the first loop, said targeted spinal correction rod implant shape, or, for subsequent simulation loop or loops, if any, said overbent spinal correction rod implant shape resulting from the previous simulation loop, ▪and said intermediate spinal correction rod implant shape. ➢ an estimation step of a targeted spinal correction rod implant shape which is based on a patient specific spine shape correction of a patient specific spine and which includes a patient specific spine 3D modeling (91, 92), ➢ one or more simulation loops each comprising: ∘ a first simulation step of an intermediate spinal correction rod implant shape resulting from a modeling of a mechanical interaction between said patient specific spine and: ▪either, for the first simulation loop, said targeted spinal correction rod implant shape, ▪or, for subsequent simulation loop or loops, if any, an overbent spinal correction rod implant shape resulting from the previous simulation loop, ∘ a second simulation step of a spinal correction rod implant shape overbending which is applied to said targeted spinal correction rod implant shape to give a resulting overbent spinal correction rod implant shape and which is representative of a difference between: ▪either, for the first loop, said targeted spinal correction rod implant shape, or, for subsequent simulation loop or loops, if any, said overbent spinal correction rod implant shape resulting from the previous simulation loop, ▪and said intermediate spinal correction rod implant shape. ∘ a first simulation step of an intermediate spinal correction rod implant shape resulting from a modeling of a mechanical interaction between said patient specific spine and: ▪either, for the first simulation loop, said targeted spinal correction rod implant shape, ▪or, for subsequent simulation loop or loops, if any, an overbent spinal correction rod implant shape resulting from the previous simulation loop, ▪either, for the first simulation loop, said targeted spinal correction rod implant shape, ▪or, for subsequent simulation loop or loops, if any, an overbent spinal correction rod implant shape resulting from the previous simulation loop, ∘ a second simulation step of a spinal correction rod implant shape overbending which is applied to said targeted spinal correction rod implant shape to give a resulting overbent spinal correction rod implant shape and which is representative of a difference between: ▪either, for the first loop, said targeted spinal correction rod implant shape, or, for subsequent simulation loop or loops, if any, said overbent spinal correction rod implant shape resulting from the previous simulation loop, ▪and said intermediate spinal correction rod implant shape. ▪either, for the first loop, said targeted spinal correction rod implant shape, or, for subsequent simulation loop or loops, if any, said overbent spinal correction rod implant shape resulting from the previous simulation loop, ▪and said intermediate spinal correction rod implant shape.