Overview

• What you’ll learn: Customer-response time and its components, manufacturing cycle time and cycle efficiency, throughput time analysis, the theory of constraints applied to time, and the financial impact of time-based competition.
• Prerequisites: Lesson 1 — Cost of Quality
• Estimated reading time: 16 minutes

Introduction

The Grand Historian records: In the ancient art of war, the swift commander defeats the powerful one. Sun Tzu taught that speed is the essence of war — arriving first at the contested ground, striking before the enemy can react. In modern commerce, time is the ultimate scarce resource. The company that delivers faster, develops products faster, and responds to customers faster will dominate markets where quality and cost are equal.

Horngren (Chapter 19) presents time-based competition as a strategic weapon that integrates with quality and cost management. Time, quality, and cost form the “iron triangle” of operations — improving one without addressing the others is futile.

Customer-Response Time

Customer-response time is the duration from when a customer places an order to when the product or service is delivered. It consists of two components:

• Receipt time (order processing): Time from order placement to the start of production or fulfillment.
• Manufacturing (or fulfillment) cycle time: Time from the start of production to delivery.

Reducing customer-response time directly increases customer satisfaction and often allows premium pricing. In many industries, the fastest responder captures disproportionate market share.

Manufacturing Cycle Time

Manufacturing cycle time decomposes into four activities, only one of which adds value:

Manufacturing Cycle Efficiency (MCE)

MCE = Processing Time / Total Manufacturing Cycle Time

World-class manufacturers achieve MCE of 30-50%. Many companies operate at 5-10% — meaning 90-95% of cycle time is non-value-added waste. Wait time is typically the largest component — products spend most of their “manufacturing” time simply waiting in queues.

太史公曰：The messenger who takes ten days to deliver a dispatch spends nine of them waiting at relay stations and one actually riding. The message is the same whether it takes one day or ten, but the general who receives it in one day wins the battle. Manufacturing cycle efficiency measures how much of the journey is actual riding.

Throughput and Bottleneck Analysis

Throughput is the rate at which the system generates finished goods. It is limited by the bottleneck — the slowest operation in the production process.

Time-based improvement strategies:

• Reduce wait time: Smaller batch sizes, better scheduling, cellular manufacturing.
• Reduce move time: Layout optimization, bringing workstations closer together.
• Reduce inspection time: Statistical process control, poka-yoke (mistake-proofing), quality at source.
• Increase processing speed: Better equipment, process engineering, automation.
• Eliminate the bottleneck: Per TOC principles — exploit, subordinate, elevate.

Financial Impact of Time Reduction

• Lower inventory holding costs: Faster cycle time = less work-in-process inventory.
• Reduced obsolescence risk: Products spend less time in the system.
• Revenue acceleration: Faster delivery = faster cash collection.
• Premium pricing: Customers pay more for faster delivery.
• Market share gains: The fastest competitor wins in time-sensitive markets.

Key Takeaways

• Customer-response time = receipt time + manufacturing cycle time.
• Manufacturing cycle time is mostly non-value-added — wait time dominates.
• MCE = Processing Time / Total Cycle Time — world-class is 30-50%.
• Time reduction lowers costs, accelerates revenue, and enables premium pricing.
• The bottleneck determines system throughput — improve it first.

What’s Next

In Lesson 3, we move from time to inventory — JIT systems, backflush costing, and the revolution of zero-inventory manufacturing.