Author: Pavel Ryvola | Updated:
What is a Timeline and Why is it Key to Quality Management?
A Timeline is a visual tool for chronologically recording a sequence of events. In quality management and manufacturing companies, it is an absolute essential during nonconformity and claim investigations (Root Cause Analysis - RCA). It helps auditors and engineers instantly understand the storyline: when exactly the defect occurred, how long it went unnoticed, and how quickly the team reacted by implementing containment actions.
When and How to Use a Timeline in Practice?
- 8D Reports and Claim Resolution: A detailed chronology is required in step D2 (Problem Description) and D3 (Containment Actions). It shows the supplier's reaction speed.
- RCA Investigation (Root Cause Analysis): A clear record of the incident reveals hidden delays, communication failures, or process inconsistencies.
- APQP and Project Management: Planning key milestones for a new project (PPAP, serial release) broken down into calendar weeks (CW).
Standardized Statuses in Automotive (Traffic Light Logic)
To make the report understandable across departments and for customers (OEMs), we recommend color-coding events according to a universal standard:
| Category | Meaning and Usage | Practical Example |
|---|---|---|
| Process Map | Standard event before the problem occurred. | Start of serial production, shift change. |
| Red (Scrap) | The exact moment when a physical defect occurred. | Tool breakage, cooling system failure. |
| Yellow (Detection) | The moment a defect or warning was detected. | Defect detected at customer site (complaint). |
| Black (D3 Action) | Quick temporary action to protect the customer. | Introduction of 100% sorting, warehouse block. |
| Green (OK) | Permanent systemic solution preventing recurrence. | CNC program change, FMEA update. |
What's next?
A timeline is a great start to understanding context. If solving a real production problem, we recommend moving to root cause analysis using an Ishikawa Diagram after building the timeline. Then, break down deeper causes with the 5-Why method. Finally, process all findings and corrective actions into a clear 8D Report.