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Sequential Scheduler

The Sequential Scheduler is the primary scheduling engine in Velosity. It processes production orders one by one in a strictly defined order, ensuring that resources are allocated efficiently and timelines are predictable.

How It Works

The Sequential Scheduler follows a deterministic process to build the master schedule:

  1. Sorting: It gathers all active Production Orders and sorts them by their Sequence Number in ascending order.
  2. Task Processing: For each Production Order, it iterates through its Router (the list of tasks) in the order they are defined.
  3. Timing:
    • The first task starts at the earliest available time (taking into account working hours and resource availability).
    • Each subsequent task in the router starts immediately after the previous task finishes.
  4. Resource Allocation:
    • The scheduler checks the required Resources or Resource Groups for each task.
    • If a resource is already busy with a task from a higher-priority Production Order (one with a lower sequence number), the current task is delayed until the resource becomes available.
  5. Calendars: All start and end times are automatically adjusted based on:
    • Company-wide working hours and holidays.
    • Resource-specific working hours and exceptions.

Key Behaviors

Finite Capacity

The Sequential Scheduler assumes finite capacity. Since it respects resource availability, it will never double-book a person or machine. If a resource is fully utilized, new tasks are pushed later in the schedule.

Priority via Sequence Numbers

The Sequence Number is the "lever" you use to control priority. * A Production Order with Sequence 10 will always be scheduled before one with Sequence 20, regardless of their due dates or when they were created. * Changing a sequence number and re-running the scheduler will ripple changes down the entire schedule.

Auto-Shift (On Hold)

Orders marked as ON HOLD are treated specially. They are automatically shifted down the sequence to prevent them from blocking "Ready" work, while still maintaining their place in the overall queue for future planning.

Advantages

  • Predictability: You know exactly why an order is scheduled for a certain date (it's waiting for its turn in the sequence or for a specific resource).
  • Simplicity: Easy to understand and manage by adjusting a single "Sequence" value.
  • Realism: Respects the actual constraints of your shop floor (working hours and headcounts).