Analysis and Critique of the System Readiness Level

The system readiness level (SRL) developed by Sauser <;etal/> (referred to as the S&C_SRL in this paper) has recently been introduced as a system development metric on several major defense acquisition programs without having received adequate scrutiny for modeling realism and mathematical validity. The use of matrix operations on a technology readiness level (TRL) vector and an integration readiness level (IRL) matrix gives the S&C_SRL characteristics of a quantitative measure. Given that the TRL and IRL are ordinal data, these operations are meaningless, and the S&C_SRL is a potentially misleading metric. Its use can have harmful consequences on a system's development. Fortunately, there is no need for the S&C_SRL given the availability of valid qualitative models that provide visibility and valid information on both the achieved system readiness and the difficulty to achieve operational readiness; but they have limited usefulness. The effective and efficient development of technically advanced systems and upgrades of heritage systems requires a systems engineering (SE) process based on a sound quantitative assessment and management of technical, cost, and schedule risks. The use of the S&C_SRL and other flawed decision and risk analysis models is symptomatic of a mathematical vulnerability in the SE practice. Corrective actions are presented.