Lesson 7: The Product Decision Chain, Instructor Session Plan

Lesson 6 built the MTBH table and the design envelope. This lesson teaches the discipline that keeps a calculator from running the design: the decision chain, with the Product Spec Calc as step five, never step one. The one outcome every student must leave with is the reflex to reason the chain before opening the tool. If they can run the calc but reach for it first, the lesson hasn't landed. Don't demo the calculator until the room has walked the chain out loud, and when you do, make a student drive it under a little pressure.

Run of Show (60-minute baseline)

Segment	Min	What happens
The calculator-first anti-pattern	6	Read the hook aloud. Put the trap on the board: someone who can run the calc but can't say what the outputs mean has learned data entry, not product analysis. Land the driving question, can this product be conveyed, and in what order do I find out, and promise the room the order is the lesson.
The decision chain, in order	10	Write the seven steps on the board as a numbered chain: MTBH, envelope, which package drives each output, package-basics outputs, then the calc, interpret, decide. Steps one through four are thinking, five is a tool, six and seven are judgment. Make them see the calc sitting in the middle, not at the front.
Package basics, live calc demo	16	Walk weight per foot, minimum curve between-frame width, tumble angle, and roller centers, one output at a time, and only now open the Product Spec Calc for a live demo. Say out loud which package should drive each output before the number appears. Hold the deferrals: the MDR weight call is Lessons 12 and 13, rate and gap are Lesson 10, decline design is Lesson 14.
Judgment over outputs, and the OEM switch	12	Outputs conflict because different packages drive them; you don't average, you decide the envelope. Then the switch: when a system is really goods-to-person or ASRS, the conveyor calc stops being the authority and the manufacturer's tool takes over. The platforms themselves are Lesson 17; today it's just recognizing the switch.
Riverside chain walkthrough, calc last	14	Key facilitation, below. Room walks the chain on the four Riverside products with the calc closed, then opens it to confirm. Discovery, not lecture.
Forest and close	2	Every calculator in the program sits inside a chain like this one. The thinking comes first, the tool comes fifth, the decision stays theirs. Fold this into the Riverside debrief rather than running it as a separate beat.
Total	60	Baseline session. Expand with the stretch options below if you have 90 minutes.

Stretch options (for a 90-minute block):

Recognize the switch (add 10 min): hand the room a scenario that's really a goods-to-person or ASRS problem dressed up as a conveyor question. Make them catch that the Product Spec Calc has stopped applying and name what tool takes over. This is the habit that saves a whole proposal from being sized on the wrong calculator.
Drive it under pressure (add 10 min): after the demo, hand the calc to a student and give them a fresh three-carton mix. Make them narrate which package drives each output as they enter it. A student who has only watched you run it doesn't yet know how to use it.
Conflict resolution (add 10 min): give the room two outputs that genuinely conflict and make them resolve the envelope by analyzing the volume behind each extreme, then write a recommendation that leaves the final call to the customer.

KEY TEACHING MOMENT | STOP THE HAND THAT REACHES FOR THE CALCULATOR

The moment a student reaches for the calculator first, stop them. Don't lecture. Ask four questions: what's the smallest package, what's the heaviest, what's the conveying surface, and which package drives each output. They can't answer correctly without the analysis, and that's the entire point of the exercise. The questions expose the gap between running a tool and understanding a product.

Only after the room has reasoned the chain out loud do you open the Product Spec Calc and run it live. Then hand it off and make a student run it under a little pressure with the class watching. A student who has watched you run it once but never run it themselves doesn't know how to use it. The reflex you're building is thinking first, tool fifth, every time.

WATCH-FORS

Three failure modes, all the same root: reaching for the tool before doing the thinking. Catch each one live and drive it back to the chain.

Students who select a technology or open the calc before they've analyzed the product. Stop them and run the four questions. Every time. It's the habit the lesson exists to build.
Students who treat calculator outputs as final answers and apply no margin or judgment. A number off the tab is a parameter, not a decision. Make them say what package produced it and whether that package even belongs in the system.
Students who try to run conveyor math on what's really a goods-to-person or ASRS problem. Make them recognize the switch and reach for the manufacturer's tool instead.
Reinforce the calculations-as-a-starting-point habit here. It's introduced across the program and lands hard in Part VI. Every time a student wants the number to be the answer, remind them the number is where the judgment starts, not where it ends.

RIVERSIDE FACILITATION | WALK THE CHAIN, CALC CLOSED

Have the room walk the chain on the four Riverside products with the calc closed, then open it only to confirm what they already reasoned. The discovery is the lesson, so don't tell them, ask. Steer them to find on their own that the Small Case drives roller centers and the smallest gap, and that the Large Case drives belt width and curve between-frame width. When someone says it, make them justify it from the dimensions, not from memory.

Flag the Tall Case for the mezzanine decline through its tumble angle, then hold the line: the decline itself is designed in Lesson 14, not today. If a student starts reaching for rate or gap numbers off the same tab, redirect them, that's the diagram phase in Lesson 10. Keep the beat on package geometry and the order of operations.

INSTRUCTOR ONLY | DO NOT SHARE WITH STUDENTS

The decision-chain walkthrough each student writes here, and the calc outputs they check it against, are project-folder artifacts. Keep steering them to file this Riverside work into the same running note they've kept since Lesson 1, dated and organized. Frame it as simply what professional engineers do.

Don't tell them where the note is heading. The reasoning they capture now, which package drove which output and why, is the raw material the capstone pays off on later. It lands hardest for the students who kept the artifacts without being told why. Your only job is to make the habit feel normal.