Planning in Excel is possible. However, in rapidly changing and highly constrained production environments, this approach quickly becomes insufficient.
Common issues include assuming infinite capacity, ignoring setup and maintenance constraints, increasing manual workload during revisions, and detecting bottlenecks too late.
With APS, finite-capacity planning, automatic rescheduling, and scenario simulation become possible.
The key question is: Are you spending your day following an Excel plan, or managing deviations proactively?