A method of forming a passive strain indicator on a preexisting turbine component , the preexisting turbine component comprising an outer surface comprising a first material, the method comprising: directing a flow of a carrier fluid towards a first location within a portion of the outer surface of the pre-existing turbine component , the flow of carrier fluid carrying a powder, the powder comprising a second material that is different from and compatible with the first material; emitting light in the form of a laser beam from a laser source; directing the emitted laser beam towards the first location within the portion of the outer surface of the pre-existing turbine component to melt the powder carried in the flow of the carrier fluid onto the outer surface of the pre-existing turbine component at the first location within the portion of the outer surface of the pre-existing turbine component , whereby a first fiducial marker of the passive strain indicator is formed at the first location; directing the flow of carrier fluid towards a second location within the portion of the outer surface of the pre-existing turbine component ; and directing the emitted laser beam towards the second location on the outer surface of the pre-existing turbine component to melt the powder carried in the flow of the carrier fluid onto the outer surface of the preexisting turbine component at the second location, whereby a second fiducial marker of the passive strain indicator is formed at the second location; wherein the portion of the outer surface defines an analysis region on the outer surface of the component , the analysis region defines a gage length (G), and each of the first fiducial marker and the second fiducial marker has a maximum diameter (MD) of between one-tenth and one-twentieth of the gage length (G). directing a flow of a carrier fluid towards a first location within a portion of the outer surface of the pre-existing turbine component , the flow of carrier fluid carrying a powder, the powder comprising a second material that is different from and compatible with the first material; emitting light in the form of a laser beam from a laser source; directing the emitted laser beam towards the first location within the portion of the outer surface of the pre-existing turbine component to melt the powder carried in the flow of the carrier fluid onto the outer surface of the pre-existing turbine component at the first location within the portion of the outer surface of the pre-existing turbine component , whereby a first fiducial marker of the passive strain indicator is formed at the first location; directing the flow of carrier fluid towards a second location within the portion of the outer surface of the pre-existing turbine component ; and directing the emitted laser beam towards the second location on the outer surface of the pre-existing turbine component to melt the powder carried in the flow of the carrier fluid onto the outer surface of the preexisting turbine component at the second location, whereby a second fiducial marker of the passive strain indicator is formed at the second location; wherein the portion of the outer surface defines an analysis region on the outer surface of the component , the analysis region defines a gage length (G), and each of the first fiducial marker and the second fiducial marker has a maximum diameter (MD) of between one-tenth and one-twentieth of the gage length (G). <EOS>