Let $1 \le s < t$, $N \ge 1$ be integers and a complex electronic circuit of size $t$ is said to be an $s$-active, $\; s \ll t$, and can work as a system block if not more than $s$ elements of the circuit are defective. Otherwise, the circuit is said to be an $s$-defective and should be replaced by a similar $s$-active circuit. Suppose that there exists a possibility to run $N$ non-adaptive group tests to check the $s$-activity of the circuit. As usual, we say that a (disjunctive) group test yields the positive response if the group contains at least one defective element. Along with the conventional decoding algorithm based on disjunctive $s$-codes, we consider a threshold decision rule with the minimal possible decoding complexity, which is based on the simple comparison of a fixed threshold $T$, $1 \le T \le N - 1$, with the number of positive responses $p$, $0 \le p \le N$. For the both of decoding algorithms we discuss upper bounds on the $α$-level of significance of the statistical test for the null hypothesis $\left\{ H_0 \,:\, \text{the circuit is $s$-active} \right\}$ verse the alternative hypothesis $\left\{ H_1 \,:\, \text{the circuit is $s$-defective} \right\}$.