Using sensing and active feedback control within each of these subsystems can compound the process repeatability and reliability. Ideally, the metal components built using SLM should be fully dense, with isotropic (or tailored) mechanical properties, tailored surface roughness and high dimension accuracy.
The table below  summarises the main sensing and controls currently available to monitor SLM machines.
Laser system delivery
Sensors and remedial actions
Build chamber environment
Sensors and Remedial actions
Sensors and remedial actions
 Edward W Reutzel Abdalla R Nassar, (2015),"A survey of sensing and control systems for machine and process monitoring of directed-energy, metal-based additive manufacturing", Rapid Prototyping Journal, Vol. 21 Issue 2
 Bontha, S., Klingbeil, N.W., Kobryn, P.A., Fraser, H.L., 2006. Thermal process maps for predicting solidification microstructure in laser fabrication of thin-wall structures. J. Mater. Process. Technol. 178, 135–142.
 Thompson, J.R., 2014. Relating Microstructure to Process Variables In Beam-Based Additive Manufacturing of Inconel 718 (Master Of Engineering). Wright State University.
 Paschotta, R., 2008. Laser Noise, in: Field Guide to Lasers. Bellingham, Washington, pp. 116– 120.
 Johnstone, I., 2000. Beam sampling & process monitoring in laser material processing applications. Ind. Laser Solut. 20, 34–35.
 Ophir Photonics, 2014. Ophir Photonics’BeamWatchTM, Industry’s First Non-Contact Industrial Beam Monitoring System for Very High PowerYAG and FiberLasers.
 Hofmeister, W.H., MacCallum, D.O., Knorovsky, G.A., 1999. VIDEO MONITORING AND CONTROL OF THE LENS PROCESS. Presented at the American Welding Society 9th International Conference of Computer Technology in Welding, Detroit, Mi.
 Hu, D., Kovacevic, R., 2003. Sensing, modeling and control for laser-based additive manufacturing. Int. J. Mach. Tools Manuf. 43, 51–60.
 Colodron, P., Fariña, J., Rodríguez-Andina, J.J., Vidal, F., Mato, J.L., Montealegre, M.A., 2011. Performance improvement of a laser cladding system through FPGA-based control, in: IECON 2011-37th Annual Conference on IEEE Industrial Electronics Society. pp. 2814–2819.
 Araujo, J.R., Rodriguez-Andina, J.J., Farina, J., Vidal, F., Mato, J.L., Montealegre, M.A., 2012. FPGA-based laser cladding system with increased robustness to optical defects, in: IECON 2012-38th Annual Conference on IEEE Industrial Electronics Society. Montreal, QC, pp. 4688–4693.
 Hofman, J.T., Pathiraj, B., van Dijk, J., de Lange, D.F., Meijer, J., 2012. A camera based feedback control strategy for the laser cladding process. J. Mater. Process. Technol. 212, 2455–2462.
 Bi, G., Gasser, A., Wissenbach, K., Drenker, A., Poprawe, R., 2006. Identification and qualification of temperature signal for monitoring and control in laser cladding. Opt. Lasers Eng. 44, 1348–1359.
 Bi, G., Schürmann, B., Gasser, A., Wissenbach, K., Poprawe, R., 2007. Development and qualification of a novel laser-cladding head with integrated sensors. Int. J. Mach. Tools Manuf. 47, 555–561.
 Bi, G., Sun, C.N., Gasser, A., 2013. Study on influential factors for process monitoring and control in laser aided additive manufacturing. J. Mater. Process. Technol. 213, 463–468.
 Song, L., Bagavath-Singh, V., Dutta, B., Mazumder, J., 2011. Control of melt pool temperature and deposition height during direct metal deposition process. Int. J. Adv. Manuf. Technol. 58, 247–256.
 Bartkowiak, K., 2010. Direct laser deposition process within spectrographic analysis in situ. Phys. Procedia 5, 623–629.
 Song, L., Mazumder, J., 2011. Feedback control of melt pool temperature during laser cladding process. Control Syst. Technol. IEEE Trans. On 19, 1349–1356.
 Nassar, A.R., Spurgeon, T.J., Reutzel, E.W., 2014a. Sensing defects during directed-energy additive manufacturing of metal parts using optical emissions spectroscopy, in: Solid Freeform Fabrication Symposium Proceedings, University of Texas, Austin, TX.
 Nassar, A.R., Spurgeon, T.J., Reutzel, E.W., 2014b. Intra-Layer Control via Alteration of Path Plan in Directed Energy Deposition