Project Management, Lean & JIT Comprehensive Study Notes

Project Management & Supply Chain Interface

Supply‐chain questions driving project success:
- When is equipment or supplies required within the project timeline?
- Exactly how much lead-time is necessary for every item or activity?
- When should purchase orders be released to suppliers?
- Is there exposure to disruption anywhere in the supply chain for equipment, materials, or labour?
- Direct link to Supply & Demand planning: poor answers inflate inventory, extend durations, or create stock-outs.

Project Scheduling Tools: Gantt, AON, Critical Path

Sample House-Construction Gantt (selected lines)
- Overall task: “Construction of a House” — $\text{Duration}=20\;\text{days},\;\text{Start}=\text{Feb }13,\;\text{End}=\text{Mar }12$
- Internal Work Package (18 d, Feb 13 – Mar 10)
- Electrical (12 d, Feb 13 – Feb 28)
  - Rough-in electrical (4 d)
  - Install & terminate (3 d)
  - HVAC equipment (5 d)
- Plumbing (18 d, Feb 13 – Mar 10)
  - Rough-in plumbing (3 d)
  - Set fixtures (4 d, Mar 3 – Mar 6)
  - Test & clean (2 d, Mar 7 – Mar 10)
- Foundation (10 d, Feb 13 – Feb 26)
- Excavate (6 d)
  - Pour concrete (3 d, Feb 13 – Feb 17)
  - Cure & strip forms (3 d, Feb 18 – Feb 20)
- Steel erection (10 d)
  - Steel columns (2 d, Feb 21 – Feb 24)
  - Beams (4 d, Feb 21 – Feb 26)
Activity-on-Node (AON) network (Figure 3.20):
- Each node shows: Earliest Start (ES), Earliest Finish (EF), Latest Start (LS), Latest Finish (LF), Step Duration.
Critical Path illustration:
- Path Start → A → C → E → G → End is critical; total project time $=15\;\text{units}$ .
- Slack values displayed per node (e.g., D & B each have 1 unit slack; H has 0; etc.).
“Slack” (float) concept:
- $\text{Slack}=LS-ES=LF-EF$ — time a task can slip without delaying the whole project.

Project Management Learning Outcomes (Week Theme)

Describe how supply-chain variability influences project performance.
Clarify the supply-chain manager’s role inside projects.
Determine the critical path & identify slack.
Explain factors that lead to good project management practice (communication, risk planning, cross-functional alignment, etc.).

Lean, JIT & Toyota Production System Overview

Two linked courses this week: “Quality 1 – Lean & Just-in-Time”.
Lean production definition:
- Integrated set of activities designed to produce high volume with minimal inventories.
- Goal: Highest quality, lowest cost, shortest lead-time by eliminating Muda (waste).
JIT (Just-in-Time) inventory model:
- Produce/ship exactly what the customer needs, exactly when needed, in exactly the required quantity.
Toyota Production System pillars:
1. Stability & Standardization
2. Jidoka (quality at source)
3. JIT production (pull, Kanban, small lots, mixed-model, visual mgmt, TPM, Poka-Yoke, 5S, root-cause analysis)
4. Involvement & respect for people (lifetime employment, level payroll, bonuses, unions, viewing workers as assets).

Lean Learning Outcomes

Illustrate lean concepts in manufacturing & supply-chain contexts.
Identify example wastes (Ohno’s 7 + 1).
Transition from Make-to-Stock (MTS) to Make-to-Order (MTO).
Explain Kanban flow & JIT inventory principles.

Lean Logic: Push vs Pull

Lean axiom: “Nothing is produced until it is needed.”
1. A customer sale pulls a unit from the final finished-goods spot.
2. This triggers production of a replacement downstream, cascading pulls upstream.
Push (MTS): build to schedule/forecast; inventories exist at each echelon.
Pull (MTO): demand signal travels upstream; no work released until downstream authorizes.
Kanban: visual signal (card, empty bin) authorizing upstream replenishment — functions like a “supermarket” of controlled inventory.

Lean Tools & Concepts

Jidoka (Autonomation): stop line, fix, find root cause, permanent solution.
Poka-Yoke: mistake-proofing; $100\%$ inspection with immediate feedback.
Heijunka: production leveling; calculate takt time $=\dfrac{\text{Available time}}{\text{Customer demand}}$ .
Standardized work, visual management.
Kaizen blitz: short, intense improvement burst; Kaikaku: radical redesign.
5S: Sort, Set-in-order, Shine, Standardize, Sustain.
Total Productive Maintenance (TPM): operator-owned equipment upkeep.

Waste (Muda): Taiichi Ohno’s 7 + 1 & TIMWOODS Mnemonic

Over-production (T): producing ahead of demand.
Waiting (I): idle time in queues.
Transportation (M): unnecessary moves.
Over-processing (W): redundant operations.
Inventory (O): excess WIP, FG, safety stock.
Motion (O): unnecessary human/robot movement.
Defects (D): rework, scrap, warranty.
Skills Underutilized (S): untapped human potential.
Shigeo Shingo quote: only the last turn of a nut tightens the bolt; the preceding turns are waste.

Variability & JIT Buffering

Variability sources: customer demand fluctuation, operations output variation, material quality issues.
Typical counter-measures in non-lean systems: extra safety stock, rework, scrap.
Lean response: attack root causes instead of buffering with inventory.

Case Study: Whirlpool – Sears Dryers (1994/95) — Push to Pull Transition

BEFORE (Push/MTS):
- Long production runs, large lots, traditional line, extended firm lead-time.
- Single-model truckloads from Cambridge plant to Sears DCs on VMI basis.
- PO’s based on forecast; high FG at plant & DC; weekly truck transfers.
TRANSITION STEPS:
1. Customer orders captured daily & centralized.
2. Plant shifts to cellular layout, short runs, “lot size = 1”.
3. DC becomes cross-dock; mixed-model TLs shipped daily.
4. Blanket order remains, but individual consumer orders dropped on factory for next-day delivery.
AFTER (Pull/MTO):
- Responsive supply chain, short firm time, double-digit Inventory-Turnover Ratio.
- Mixed truckloads, minimal FG, make-to-order.

JIT Concepts Across Core Processes

Manufacturing:
- Lot size reduction, SMED, cellular work cells, leveled/mixed model, aggregate planning, postponement, visual Kanban, TPM.
Product Design:
- Design for manufacturing, robust design, yield maximization, parts standardization/modularity, sustainability/EOL.
Logistics Network:
- Cross-dock, mixed TL/LTL, inbound milk-runs, Supply Chain Event Mgmt (SCEM) alerts, compliance-based metrics.
Supply Base:
- Partnerships, CPFR, short-lead replenishment, supplier sequenced delivery, co-location.
Quality Programs:
- Cost of quality components (prevention, appraisal, internal & external failure), quality at source, mistake-proofing, 5S culture.

Benefits & Risks of JIT (Pull)

Benefits:
- Simplified scheduling; responds only to real demand; no item-level forecast (family-level still needed).
- Makes quality & capacity problems visible immediately.
- Prevents WIP from piling at bottlenecks.
Risks:
- Greater exposure to catastrophic events (strikes, fires, borders, weather).
- Higher dependency on suppliers; tougher to globalize sourcing.
- Cost pressure (smaller lots, increased shipments).
- Requires cultural change for both management & shop floor.
- Not all processes/suppliers are JIT candidates; MTS may still be optimal when coordination costs or variability are high.

JIT Outcomes

Quantifiable:
- Smaller lot sizes, shorter lead times, lower inventories, reduced scrap, $\text{Lower Total Cost}$ .
Intangible:
- Empowered teams, culture of zero waste, improved revenues & customer satisfaction.

Visual Metaphors & Media Cues

“Sea of Inventory” graphic: high inventory hides rejects, poor layouts, breakdowns, over-processing, poor capacity, waiting, skill gaps, delays.
Bloomberg Quicktake “How Toyota Changed The Way We Make Things” & other YouTube links reinforce historical context.
Kahoot & video examples used for interactive learning.

Wrap-Up: Variance + Waste = Enemies of Lean

Lean strives to eliminate both variance (unpredictable outcomes) and waste (predictable but unnecessary activities).
Achieving stability, flow, and pull converts a push, forecast-driven system into a responsive, cost-efficient one.