Lean Factory Challenge Worksheet
Intro to Manufacturing • Unit 4
LEAN SYSTEMS & WIDGET REDESIGN
Class Pacing: 40 Minutes
Student Investigation Sheet
Student Name:
Period:
Factory Team:
PART 1
Foundations of Lean Manufacturing
Originating in the Toyota Production System (TPS), Lean manufacturing is a systematic methodology focused on eliminating waste (Muda) without sacrificing productivity. Every activity in a factory is categorized as either Value-Added (steps the customer is willing to pay for that physically transform the product) or Non-Value-Added (wasteful delay, rework, movement, or storage).
1 Value
Defined strictly from the paying customer’s perspective.
2 Value Stream
Map all physical & information steps from raw card to widget.
3 Flow
Ensure units move steadily without bottlenecks or buffers.
4 Pull
Produce downstream items only when requested by demand.
5 Kaizen
Continuous incremental pursuit of zero defects & perfection.
PART 2
Identifying the 8 Wastes (TIMWOODS)
Core industrial engineering diagnostic tool
T - Transport:
Unnecessary moving of index cards across desks.
I - Inventory:
Excess piles of WIP (work-in-progress) or raw materials.
M - Motion:
Unnecessary reaching, bending, or searching for staplers.
W - Waiting:
Assemblers idle while waiting for folding to finish.
O - Overproduction:
Making more widgets than ordered (the worst waste!).
O - Overprocessing:
Adding extra folds or double checks not in product spec.
D - Defects:
Torn cards, misaligned staples, scrapped inventory.
S - Skills / Talent:
Ignoring team ideas or keeping fast workers bottlenecked.
Widget Factory Diagnostic Audit
Recall your group's performance during the Index Card Factory simulation and financial accounting. Analyze the three actual classroom factory observations below:
| Simulation Observation | TIMWOODS Waste Type | Financial & Operational Impact |
|---|
| | |
| Scenario A: The Card Pile | | |
Station 1 folded cards at top speed, accumulating 18 folded cards on the desk while the hole-punch operator struggled to keep up.
|
Primary Waste:
Secondary Waste:
|
Why does this tie up cash or hide quality errors?
|
|
Scenario B: Quality Gate Rejection
At the end-of-line inspection station, 5 completed index card widgets were rejected because staples were 0.5 inches off specification.
|
Primary Waste:
Root Cause Category:
|
How did scrapped cards impact your group's net profit?
|
|
Scenario C: Desk Tool Hunt
The stapler operator stood up and reached across two classmates' desks every time a staple reload or ruler measurement was required.
|
Primary Waste:
Lean Countermeasure:
|
What 5S workspace adjustment solves this motion waste?
|
Unit 4: Advanced Manufacturing Systems Page 1 of 2 • Lean Principles & Waste Identification Lean Manufacturing Principles
Factory Engineering • Application Lab
PUSH VS. PULL & REAL-WORLD SCALING
Kaizen Redesign Protocol
PART 3
Push Production vs. Pull (Kanban) Production
PUSH SYSTEM (Batch & Queue)
Workstations produce as fast as possible to a quota, "pushing" unfinished widgets onto downstream desks regardless of whether the next person is ready.
Impact: Huge Work-In-Progress (WIP) piles, delayed quality feedback, tied-up cash.
PULL SYSTEM (Just-In-Time / Kanban)
Downstream stations signal upstream stations with a trigger (Kanban card, bin, or light) only when a customer places an order. No demand = zero production.
Impact: Minimal WIP inventory, immediate defect isolation, fast cycle times.
Challenge: Engineering the Index Card Factory 2.0
Your team is re-running the index-card widget assembly line. Design two specific Lean countermeasures to eliminate bottlenecks:
1. Takt Time & Line Balancing: If folding took 10s per card but hole-punching and stapling took 26s, folding causes a bottleneck. How would you re-allocate team roles to balance the line?
2. Visual Kanban Mechanism: Design a simple physical signal (e.g., tape square, index-card placeholder limit of 2) between Station 1 and Station 2 to enforce a strict PULL flow.
PART 4
Real-World Case Study: Modern Production Lines
From Index Cards to Everyday Products: Companies like Toyota, Boeing, and custom athletic footwear brands (such as Nike) apply these exact Lean concepts. In traditional sneaker manufacturing, factories stored millions of components in overseas warehouses (Push). Modern plants use One-Piece Flow and digital Kanban to build custom shoes only after customer checkout (Pull), catching stitching errors after 1 shoe instead of thousands of defective pairs.
A. Financial Risk of Inventory: Why is storing 1,000 finished widgets in inventory riskier than maintaining a flexible pull line producing 50 per day? (Connect cash flow, damage, and customer changes).
B. Personal Kaizen Proposal: Propose ONE specific, zero-cost continuous improvement idea (jig, folding template, standardized sequence, or desk arrangement) for your group.
Online Manufacturing Extension & Web Investigation Links
Toyota Production System global.toyota/en/company/vision-and-philosophy/production-system Original TPS pillars: Jidoka & JIT.
Lean Enterprise Institute lean.org/lexicon-terms Industrial glossary: 8 Wastes & Takt.
NIST Manufacturing Extension nist.gov/mep/manufacturing-services/lean U.S. manufacturing continuous improvement.
Continuous Improvement: Plan-Do-Check-Act (PDCA) Page 2 of 2 • Pull Systems & Real-World Scaling Widget Factory Redesign Lab
