PYTHON · NUMPY

Sequencing a process plan

Order a multi-operation plan into a valid sequence, choosing setups, and justify why the order is forced by datums and the surfaces each operation creates.

01Challenge

Five scrambled operation cards: FACE_TOP, DRILL_4xM4, POCKET, DEBURR, CUTOFF_STOCK. Drag them into an order, pick a setup for each, Run Plan, and get every feature produced with no INFEASIBLE flag. Drill or pocket before facing → DATUM_NOT_ESTABLISHED; deburr first → nothing to deburr; cutoff first → you lose the clamping tail.

02Model

Five operations: 120 possible orders, and almost all are impossible, not just slower. Every dimension is measured from a datum (a hole located from a face is only as accurate as that face), so the operation that creates a datum must come before every operation that uses it.

Look at the dependencies: facing creates the reference drilling and pocketing need; deburring needs the edges those ops create, so it comes after; cutting the part free destroys your clamping surface, so it comes dead last. A setup is one clamping; every re-fixture spends time and risks losing alignment, so do as much as possible in one setup.

Order operations into a valid sequence.

03Guided practice

Step A (worked): each op declares requires/produces; FACE_TOP produces datum_top, DRILL/POCKET require it, DEBURR requires holes+pocket, CUTOFF destroys the fixture; validate sequence FACE_TOP→DRILL→POCKET→DEBURR→CUTOFF.
Step B (fade): swap so DRILL runs before FACE_TOP, read the exact flag, restore; then put DEBURR first and predict the flag.
Step C (independent): housing_v2 needs features on top AND bottom; introduce a second setup after establishing the bottom datum, keeping setups minimal.

04Feedback

PASS WHEN datum_violations=0, fixture_violations=0, features_complete=total, unreachable_features=0, setups ≤ min_required, infeasible=False, on seed 2303.

If your run fails, check:

DATUM_NOT_ESTABLISHED: DRILL_4xM4 requires 'datum_top' but FACE_TOP runs later. Move FACE_TOP before DRILL_4xM4.
DEBURR_PREMATURE: DEBURR requires edges from {holes, pocket}, neither exists yet at its position. Sequence DEBURR after DRILL and POCKET.
FIXTURE_LOST: operations run after CUTOFF_STOCK, which destroys the fixture. Move CUTOFF_STOCK to the end.
EXTRA_SETUP: 3 setups used; the part requires only 2. Group SETUP_A-reachable ops together to remove a re-clamping.

05Retrieve & space

From 2.1: the POCKET op is your 2.1 toolpath; name the tool-radius constraint that still applies wherever the pocket sits → tool radius ≤ 4 mm corner.
From 2.2: which parameter would you watch hardest drilling deep holes? → depth-driven force / peck depth (ties to overload).
From M3 preview: if FACE_TOP is skipped, do hole-position tolerances get easier or harder? → harder; variation references a rough surface.

06Mastery & project

On housing_v2 (two-setup part), the process plan grades datum_violations=0, fixture_violations=0, features_complete=total, unreachable_features=0, setups ≤ min_required, infeasible=False, and justify why the second setup is introduced where it is. Completes the M2 module gate.

The spine the capstone hangs on: in M5 the factory runs exactly this plan at volume; a needless setup shows up as cycle time and cost, and a datum done right keeps yield high. Banks the validated housing_v2 plan.

← Process parameters Tolerances: the band a part must live in →

PYTHON · NUMPY

Sequencing a process plan

A topological validator over requires/produces/destroys plus a setup-reachability check, the same one the autograder uses. Edit your order and run.

You read

the arrays and values already in scope

You change

the code you write in each cell

Fixed

the dataset and the checks that grade you