In line with the trend toward continuous miniaturization and price reduction, it is crucial to analyze the impact of uncertainties on the performance of electrical circuits. Performance is evaluated for the worst-case scenario and in the frequency domain by computing upper and lower bounds. The purpose is not only to propose a method for the worst-case tolerance analysis but also to provide an efficient and a suitable tool for electrical engineers that can be easily applied to realistic electrical engineering problems. The proposed method is based on the robust analysis method (so-called mu-analysis) for which well known and efficient algorithms exist. However in order to apply it, the problem under consideration has to be transformed in a standard minimal so-called LFT representation. Its derivation is a difficult task even for control systems engineers. This paper proposes a transparent and systematic LFT derivation procedure for users based only on their knowledge of electrical engineering. At the end of this paper, an industrial example is provided, which reveals the benefits and the efficiency of the proposed approach, and how it can be applied to any linear electrical circuit.