The timeframe for all planning calculations is the work schedule. If the schedule is incorrect, no plan can be correct; because capacity calculations, lead time calculations, and delivery date calculations are all derived from this schedule.
Factory calendar: Working days, public holidays, annual leave periods, planned maintenance shutdowns, and special occasions.
Shift patterns: Daily work schedules, break times, handover times, and night shift differences.
Resource-based calendar: Each workstation can have its own work schedule; some machines can operate in three shifts, while others operate in one shift.
Capacity definition: Calculation of net capacity remaining after deducting breaks and planned shutdowns from the shift duration.
Capacity utilization rate: What percentage of theoretical capacity is considered usable in the planning. Assuming 100% means the plan will be flawed from day one.
Exception management: Scheduling situations such as extra shifts, weekend work, and capacity reductions due to malfunctions.
Multi-calendar structure: Different calendars for the facility, business center, suppliers, and transportation working together.
Realistic capacity ratio
The most common mistake in planning is assuming that capacity will be 100% available. In reality, no machine produces for its entire planned duration: adjustments, cleaning, minor downtimes, material waiting, and quality control are inevitable.
A sound approach is to reflect a usage rate calculated from past actual data in the calendar. This rate is often lower than expected and can be unsettling for management when first calculated; however, it is a prerequisite for a realistic plan .
2. Production network
In businesses with multiple facilities, external workshops, or warehouses, production takes place not at a single point, but across a network. Modeling this network is essential for accurate planning.
Inter-facility supply relationships: Defining which materials are produced at which facility and to which facility they are shipped.
Sourcing rules: When the same product can be produced in multiple facilities, the rule that determines which one to choose is: cost, capacity, distance, quality, or customer constraints.
Transfer times and costs: Including inter-facility transportation in the plan.
Integration of subcontracting workshops into the network: External operations becoming part of the plan with their own timeline and capacity.
Central and local planning: Supporting hybrid models such as centralized master planning and on-site planning.
Network-level visibility: Total inventory, total capacity, and total load can be monitored across the network.
Load balancing: When a facility exceeds its capacity, the work can be shifted to an alternative facility.
Benefit to the customer
Realistic delivery dates. When the calendar and network are modeled correctly, the given dates will hold.
Flexible capacity. Congestion at one facility can be balanced across the network.
The right cost. The choice of production location is evaluated along with its cost impact.