\section{Method} To repair a DTMC $\mathcal M$ for a property $\phi$, we generate a parametric DTMC $\mathcal M'$ which is like $\mathcal M$ but adds a unique parameter to each transition. For instance, if $s\to s'$ in $\mathcal M$ with probability $p$, in $\mathcal M'$, this transition has probability $p+v_{s,s'}$, where $v_{s,s'}$ is not a parameter in $\mathcal M$. We let $\mathcal V$ denote the set of all parameters $v_{s,s'}$ with $s\to s'$ in $\mathcal M$. Cost functions can be specified as minimalisation goals on $\mathcal V$. For the examples in the previous section, we can define: \begin{equation} \textsl{SSE}(\mathcal V) \stackrel{\text{def}}{=} \sum_{v\in\mathcal V} v \end{equation} \begin{equation} \textsl{MSE}(\mathcal V) \stackrel{\text{def}}{=} \frac{\textsl{SSE}(\mathcal V)}{|\mathcal V|} \end{equation} \begin{equation} \textsl{NMT}(\mathcal V) \stackrel{\text{def}}{=} \sum_{v\in\mathcal V, v\ne 0} 1 \end{equation}