Reliability Estimate for the Thirty Meter Telescope

The Thirty Meter Telescope is a large and complex system with thousands of optical, mechanical, electrical and electronic parts required for its operation. It is vital that the system operates reliably such that only a small percentage of time is lost to unexpected failures. The loss of time depends not only on the reliability of each part, but also how the system is designed to be robust against failure so that it can continue to operate in a degraded mode in the presence of a failure, and also how the operational model is designed to be adaptable so it can deal with unexpected failures. TMT has developed a reliability model that accounts for degraded operation of the telescope and a flexible operations model. An estimate of the system reliability has been made using this model, and the lessons learned in developing the model used to develop a straightforward method for suppliers to assess their systems susceptibility to failures and estimate the subsystem reliability.