Erratum for “Productivity Scheduling Method: Linear Schedule Analysis with Singularity Functions” by Gunnar Lucko

The corrected differences of the intercepts are $\{7,4,7,7,5\}$. These difference equations describe the white trapezoidal areas in Fig. 5. See also Fig. 6, in which they appear as white triangles after consolidation. All subsequent equations in the paper remain correct; the erroneous differences of the intercepts become zero in the following differentiation to find the minima of the trapezoids.

The following equations are correct but are rewritten in a longer form to simplify verification. These difference equations describe a figure analogous to Fig. 5 but for amount buffers. See also Fig. 7, in which these differences appear as white triangles after consolidation. Note that here the activity equations of Eqs. (5)–(10) and their amount buffer equations are alternatingly stacked, with slightly different intercepts of $y(x)=\{0,7,11,18,25,30\}$ for activities $\{A,B,C,D,E,F\}$, per Table 3. This results from the “plateau” of the amount buffers, which constitutes their maximum value for stacking and is different from the time buffers