How to Protect a Due Date With a Buffer in EDGEBIC

To protect a due date with a buffer in EDGEBIC, anchor the job to its constraint operation so the engine inserts a shipping buffer between the bottleneck and the ship step. EDGEBIC by User Solutions also inserts a constraint buffer in front of the bottleneck, and you can add further slack with routing queue time and by planning the constraint below full load. The shipping buffer is the piece that specifically guards the promise date against post-constraint variation.

This is the buffer procedure. For the mechanism and how buffers interact with direction, read TOC buffers and direction precedence in EDGEBIC; to set the anchor itself, see how to anchor a job to a target start date. It is one of the task guides in the EDGEBIC how-to hub.

Before You Start

The Three Buffers, and What Each Protects

The shipping buffer is the one to reach for when a customer keeps getting deliveries late despite an on-time plan.

Step by Step: Add Buffer Protection

1. Confirm the constraint work center is marked as a bottleneck in its editor.
2. Anchor the job's bottleneck operation to a target date using Set Anchor for Selected Jobs on the Workcenter Details tab.
3. Run Schedule + Re-Schedule for the job.
4. The engine pins the anchor at its target, inserts the constraint buffer in front and the shipping buffer after, and schedules upstream backward and downstream forward around them.

When dynamic sizing is active and the anchored work center is the genuine constraint, the constraint buffer is roughly half the upstream path, the shipping buffer about a quarter of the downstream path, and the feeding buffer around a tenth of the upstream path on the direct feeder. When the anchored resource is not the tightest one, small fixed values are used instead.

Complementary Levers That Add Slack Anywhere

Not every job is anchored, so keep these universal buffering tools in mind:

• Queue time on a routing step adds a deliberate wait after an operation, which spaces steps out and absorbs small overruns. See queue time as a scheduling lever.
• A due-date margin means entering the promise a little later than the earliest possible finish, so the plan carries slack you can see in the Days Late column.
• Planning the constraint below full load leaves recovery room. Industry practice for finite-capacity planning is to load a resource to roughly 80 to 85 percent of the clock and keep the rest for breakdowns, rework, and changeover drift.

How to Check It Worked

1. Open the anchored job in Job View and confirm a visible gap sits between the constraint operation's end and the first downstream step. That gap is the shipping buffer.
2. Confirm a gap also sits in front of the anchor, absorbing upstream variation.
3. Read Days Late. With the shipping buffer in place, the job's committed end should land before the due date with margin rather than exactly on it.
4. Simulate a small upstream delay in your head: if an upstream step ran an hour late, the constraint buffer should mean the anchor still starts on time.

Common Mistakes and Gotchas

• Expecting buffers on a plain forward job. The three TOC buffers only exist inside anchor scheduling. If the job is not anchored, use queue time and a due-date margin instead.
• Assuming buffers are always present. Dynamic buffer sizing is a Theory of Constraints behavior tied to anchoring. When it is not active, the anchor still pins the date but adds no padding, and the plan runs tight. Confirm you are actually seeing gaps.
• Anchoring the wrong work center. If the anchored resource is not the tightest one for that job, the buffers fall back to small fixed values rather than demand-proportional ones. Confirm the constraint is genuinely the bottleneck.
• Padding everything. A buffer on every step is just a fat plan that hides where the real risk is. Concentrate protection around the one constraint and the promise, which is exactly what the three buffers do.

For the constraint that all of this protects, read how to flag and schedule around a bottleneck and the Theory of Constraints scheduling primer.

Bring a job that keeps slipping and we will anchor and buffer it against your data in one session. Contact US to book it, or read the EDGEBIC product overview first.