🎓 Lesson 15 D5

Non-Value-Added Labor: Identifying Hidden Muda

Non-value-added labor is any work people do that doesn’t directly improve the product, service, or safety—and could be removed without harming the final outcome.

🎯 Learning Objectives

✓ Analyze time-motion study data to classify labor tasks as value-added, necessary non-value-added, or pure non-value-added
✓ Explain root causes of NVA labor using the 8 Wastes framework (DOWNTIME) applied to blasting crews
✓ Apply value-stream mapping to isolate three high-frequency NVA labor activities on a drill-and-blast shop floor
✓ Calculate labor waste percentage from crew activity logs and benchmark against industry targets

📖 Why This Matters

In open-pit mining, up to 35% of drill-and-blast crew time is spent on non-value-added activities—such as waiting for survey clearance, repositioning rigs due to poor hole layout planning, or manually transcribing blast log data twice. This hidden labor waste inflates unit costs, delays production cycles, and masks systemic flaws in blast design and supervision. Recognizing NVA labor isn’t about cutting jobs—it’s about redirecting human capacity toward precision drilling, real-time geotechnical feedback, or predictive maintenance—directly improving fragmentation quality and reducing downstream crushing costs.

📘 Core Principles

NVA labor is rooted in Lean principles adapted to mining: Value is defined by the customer (e.g., consistent muckpile size distribution meeting crusher feed specs), not internal metrics. The 8 Wastes (DOWNTIME: Defects, Overproduction, Waiting, Non-utilized talent, Transportation, Inventory, Motion, Extra-processing) provide a diagnostic lens—but must be contextualized for blasting: 'Waiting' includes idle time during blast area clearance; 'Motion' includes unnecessary walking between drill rig and control tablet; 'Extra-processing' includes redundant pre-blast checklists with overlapping safety verifications. Critically, NVA labor differs from *necessary* non-value-added work (e.g., statutory blast report submission), which must be preserved—not eliminated—but streamlined via digital automation.

📐 Labor Waste Percentage

This metric quantifies the proportion of total labor hours spent on pure non-value-added tasks—enabling prioritization of improvement efforts and tracking progress after interventions like digital blast logs or standardized crew handover protocols.

Labor Waste Percentage

LWP = (H_NVA / H_Total) × 100

Quantifies the share of total labor hours consumed by pure non-value-added activities.

Variables:

Symbol	Name	Unit	Description
LWP	Labor Waste Percentage	%	Percentage of total labor hours spent on pure non-value-added tasks
H_NVA	Pure Non-Value-Added Labor Hours	hr	Hours spent on activities with zero functional benefit and no regulatory or safety justification
H_Total	Total Labor Hours	hr	Sum of all labor hours recorded for the defined scope (e.g., per blast round or shift)

Typical Ranges:

Benchmark for high-performing mines: 5–15%

Baseline for operations with manual workflows: 20–35%

💡 Worked Example

Problem: A 12-person blast crew logged 480 total labor-hours in a shift. Time-motion analysis revealed: 192 hrs value-added (drilling, stemming, initiation setup), 144 hrs necessary non-value-added (pre-shift safety briefing, post-blast air monitoring, regulatory reporting), and 144 hrs pure non-value-added (waiting for survey team, correcting misaligned holes due to outdated drill plan, manual data re-entry into legacy system).

1. Step 1: Identify pure NVA labor hours = 144 hrs

2. Step 2: Divide by total labor hours: 144 / 480 = 0.30

3. Step 3: Multiply by 100 to express as percentage

Answer: The labor waste percentage is 30%, exceeding the industry target of ≤15% for mature blast operations.

🏗️ Real-World Application

At Newmont’s Boddington Mine (Western Australia), a 2022 Lean Blasting initiative used digital twin-assisted drill planning and integrated GIS-survey handoff protocols. Before intervention, crews averaged 22% pure NVA labor—primarily waiting for survey confirmation before drilling. After deploying automated survey-data push-to-rig tablets and synchronized daily blast maps, NVA labor dropped to 9.3% within 4 months. Crucially, this freed 1.8 FTE/shift for proactive drill bit wear analysis—reducing bit-related hole deviation by 37% and improving burden consistency.