></span></code></pre></div>
<p><img src="maturity-model_files/figure-html/unnamed-chunk-6-1.png" alt="plot fn" width="768"></p>
<p>To impose constraints, we can reformulate the function. For instance,
if we want to ensure that <span class="math inline">\(t3 \geq
t2\)</span>, we introduce dt as the difference between t3 and t2:</p>
<p><span class="math display">\[\begin{equation}
f(t; t_1, t_2, dt, k, \beta) =
\begin{cases}
0 &amp; \text{if } t &lt; t_1 \\
\dfrac{k}{t_2 - t_1} \cdot (t - t_1) &amp; \text{if 