What Is Forward and Backward Scheduling?

Imagine you’re planning a road trip. You can either pick a date you want to arrive and plan backwards, or figure out when you can leave and plan forward. That’s essentially the difference between backward and forward scheduling.

Backward Scheduling: Planning from the End Goal

What Is Backward Scheduling?

Backward scheduling is like reverse-engineering a deadline. You start with the customer’s requested delivery date and work backwards to figure out when each task (packing, loading, shipping) needs to happen so everything arrives just in time.

How It Works (Step-by-Step)

Let’s say your customer wants their order delivered on June 30th. The system calculates: 

1. Requested delivery date – transit time = Goods Issue Date
    Example: June 30 – 3 days = June 27

2. Goods Issue Date – loading time = Loading Date
    June 27 – 1 day = June 26

3. Loading Date – transportation lead time = Transportation Scheduling Date
    June 26 – 0.5 days = June 25.5

4. Loading Date – pick/pack time = Material Availability Date
    June 26 – 1 day = June 25

Real-Time Precision

Backward scheduling supports both daily scheduling (assuming 24-hour workdays) and precise scheduling, where delivery timing can be calculated down to the minute. Precise scheduling activates when working hours are defined at the shipping point.

Forward Scheduling: When Plans Hit a Snag

Why Use Forward Scheduling?

Here’s the thing: backward scheduling is Plan A. But what if your system says, “Oops! That material won’t be ready in time”? That’s where forward scheduling swoops in. If the Material Availability Date calculated is in the past—or if there’s simply no stock on that date—then forward scheduling kicks off.

How Forward Scheduling Works

Instead of starting at the customer’s desired date, it begins from the earliest date materials are actually available. From there, it moves forward, adding: - Pick/Pack time
  • Loading time
  • Transit time
  • Transportation lead time This gives you a confirmed delivery date—realistic, attainable, and system-verified.

Practical Example

Let’s say your customer wants delivery by June 30, but your warehouse is out of stock until July 3. Forward scheduling will then: - Start from July 3 (material availability)
  • Add all required lead times
  • Arrive at, say, July 7 as the earliest possible delivery date Boom. Now you’ve got a new promise date that aligns with actual supply chain capabilities.

When Are These Used?

  • Backward Scheduling: Default strategy for checking if a requested delivery date is possible
  • Forward Scheduling: Backup plan used when the backward-calculated availability date is in the past or when there's insufficient inventory

Summary Table

Feature Backward Scheduling Forward Scheduling
Start Point Customer’s requested delivery date Material availability date
Direction Moves backward Moves forward
Use Case Default for planning Used when deadlines can't be met
Objective Meet customer’s target Find the earliest realistic date

Pro Tips for Businesses Using SAP or ERP Systems

  • Define work hours for precise scheduling down to the minute.
  • Set lead times accurately in your system—small errors can lead to big delays.
  • Enable both scheduling modes to ensure flexibility in your delivery promises.

Key Takeaways

  • Backward scheduling starts from the deadline and calculates when prep needs to begin.
  • Forward scheduling starts from today (or a future availability date) and figures out the soonest a delivery can happen.
  • Most ERP systems (like SAP) use backward scheduling first, then fall back on forward if necessary.
  • Combining both ensures you're never over-promising and under-delivering.          
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