Lesson 16: Sortation, Instructor Session Plan

This is the lesson where Part IV converges: the students pick Riverside's sorter. The one outcome they must leave with is the discipline of right-sizing, running product, throughput, and footprint in that order against the full mix, not a feel and not a favorite technology. The single move that makes it land is the live matrix exercise. A student who has run the matrix once against a real mix and a real peak understands it; a student who's only seen it on a slide doesn't. Hold the fact-check line hard: there's no universal slow-medium-high pph scale, the ranges vary by vendor, and you cite the specific model when you quote a number.

Run of Show (60-minute baseline)

Segment	Min	What happens
Controls mini-brief	5	Open on the handshake and lane-full, kept shallow. A sorter doesn't sort itself: the ID system reads, the system asks where it goes, the PLC fires the divert on a timed handshake, and a full lane has to be known so nothing diverts into it. Name it, then say the depth is Part V (L22, L23). Don't teach the logic.
Hook: the two ways to get it wrong	5	Over-engineer and under-engineer, opposite directions, both expensive. Land that right-sizing is the discipline between them and it's a set of inputs, not a feel.
Filter one: product type and the matrix	16	Key teaching moment, below. Run the product handling matrix live against a real mix with a peak requirement. Make them find the minority product that eliminates a technology. This is the center of the lesson. Do not shorten it.
Filter two: throughput at peak	12	Peak not average; effective rate below published once gap and ID cycle time are in. Then the honest ranges: no universal scale, vary by vendor, compare on the manufacturer's chart, cite the model. Correct any student who quotes a single number as a standard.
Filter three: footprint and destinations	8	Line vs loop. Line needs a separate recirculation conveyor; loop carries it built in. Destination count sets length. A sorter that can't fit its destinations in the space is the wrong sorter regardless of performance.
The system around the sorter	8	The elements in sequence, accumulation through recirculation, and the hospital lane branching off. Surface the hospital lane deliberately: ask the room where the exceptions go. They omit it during sizing because it doesn't feel necessary.
Riverside selection	4	Fold into the discussion. Right-size Riverside's sorter through the three filters against the low rate and three doors. Steer them to read against the full mix, not just the Standard Case. Do not tell them. Ask.
Forest, close, CONTROLS CORNER	2	Close on restraint over sophistication, then the sorter-encoder CONTROLS CORNER: the encoder is how the sorter knows where every carton is so it fires the divert at the right instant. Deep version is L22.
Total	60	Baseline session. Use the stretch below for a 90-minute block.

Stretch options (for a 90-minute block):

The edge case that flips the selection (add 15 min): hand the room a second mix where the majority stays constant but the minority product changes, apparel one round, a large heavy tote the next, so the surviving technology flips. Running the matrix twice on the same majority is what teaches that the edge case, not the majority, drives the call.
Argue the over-build (add 10 min): give a low-rate, low-destination application and have one student make the case for a high-throughput loop sorter. Then have the room take it apart on capital and footprint. Arguing the wrong answer exposes whether they can right-size.

KEY TEACHING MOMENT | RUN THE MATRIX LIVE

Put a real product mix on the board with a peak throughput requirement, then walk the product handling matrix as a class exercise, not a slide. Have them score every technology against every product in the mix and read the rows out loud. The teaching happens when someone picks a technology that's excellent on the majority and you ask about the minority product it rates poor on.

Push the edge-case discipline until it's automatic: the minority product that a technology can't handle eliminates that technology, even at 15 percent of volume, because you can't route one carton in seven through a sorter that damages or jams it. Then surface the hospital lane on purpose. Ask where a misread or a full-lane reject actually goes. Students leave it out of early designs because it doesn't seem necessary during sizing, and the question is how you make them feel its absence before they feel it in the field.

WATCH-FORS

Five failure modes this lesson exists to catch. When you see one, drive it back to the inputs.

They select on the majority product and never score the edge case. Send them back to the full column.
They select on average throughput. The system performs at peak; make them pull the peak from the flow diagram.
They carry a previous project's sorter forward. Every application is different; the inputs pick the sorter, not the last job.
They design the sorter and forget the recirculation path and the hospital lane. Ask where the exceptions go over a full shift.
They quote a single throughput number as if there's a universal scale. Correct it to the vendor-varying, cite-the-model framing. Manual sorting, not slow automated equipment, is what sits near or below 1,800 pph.

RIVERSIDE FACILITATION | RIGHT-SIZE THE SORTER

Have the room right-size Riverside's sorter through the three filters in order, show the matrix evaluation, and justify it against a low rate and three destinations. The move to steer, without stating it, is reading the matrix against the full mix rather than the Standard Case at 78 percent. Ask which product in the mix would eliminate a technology and let them find the tall and large cases on their own. Do not tell them. Ask.

Hold scope hard. No sorter rate arithmetic, the cartons per minute, the gap and spur checks, that's Lesson 25. No hospital-lane sizing, that's Lesson 23. No specialty garment or tire sortation, that's Lesson 17. The deliverable is the technology named with the matrix evaluation and the three filters shown, nothing more.

CHECKPOINT ANSWER KEY | INSTRUCTOR ONLY

The 60/25/15 mix, 4,200 pph, 8,000 sq ft, 12 destinations. Walk the filters in order. Product: in the matrix, the carton-and-tote-strong technologies (pusher, narrow belt) rate poor on bagged apparel, so they fall out; the technologies that clear cartons, totes, and apparel together are the ones rated at least good across that row, which points at the high-density sliding shoe and the cross-belt class, with sliding shoe good on apparel. The 15 percent apparel governs because a technology that's excellent on the 85 percent but poor on apparel would fail to handle one carton in seven every shift, turning that volume into recirculation and hospital load and a field problem. Throughput: don't let them label 4,200 pph off a fixed scale; it lands in the entry-level-to-mid overlap depending on the vendor, and has to be confirmed against the manufacturer's chart for the surviving technologies, not slotted into a fixed band. Footprint: 12 destinations is a real count that pushes toward a longer line or a loop, resolved in the layout. Grade the order and the reasoning, not a single model name.
Average rate, no recirculation drawn. Sizing to the average saturates the sorter during every wave and high-volume hour; the selection input is peak from the flow diagram, and the effective rate sits below the published maximum once the gap and the ID cycle time are in, so it needs headroom. On the system: a line sorter with no recirculation and no hospital lane has nowhere to put a missed sort, a full-lane divert, or a misread, so over a shift those exceptions stack at the discharge end until the line jams and stops. The recirculation path is required on line sorters and the hospital lane is the exception destination, both designed at the flow-diagram phase. Sizing the hospital lane is Lesson 23; the rate math is Lesson 25. If a student states the conclusion the prompt withheld and defends it, that's the pass.

INSTRUCTOR ONLY | DO NOT SHARE WITH STUDENTS

Keep the Riverside project-note habit going. The sorter selection with justification is a project-folder artifact, and it's one of the highest-cost line items in the eventual proposal, so the reasoning has to survive Tom's capital review and Michael's maintenance questions. Have every student file the matrix evaluation and the technologies they ruled out, dated, in their running Riverside note.

Don't tell them where the habit leads. The students who keep the note without being told why are the ones it pays off for later. Your job is to make filing the justification feel like simply what the work is.