Practice Scenario 2.4 – Supplier Quality

📍 Scenario: Supplier Quality Issue | サプライヤー品質問題

🔹 Participants | 参加者

🧑‍💼 CEO (English) | CEO(英語)
📋 Quality Assurance Manager (Japanese) | 品質保証部長(日本語)
📦 Procurement Manager (Japanese) | 調達部長(日本語)
🏭 Factory Manager (Japanese) | 工場長(日本語)


🏭 Scene: Executive Meeting Room – Supplier Quality Issue Discussion | 会議室 – サプライヤー品質問題の議論

📝 (A meeting room with a “Supplier Quality Report” displayed on a digital screen. Data shows increasing defect rates in raw materials from a key supplier. The CEO looks frustrated, while the Quality Assurance, Procurement, and Factory Managers prepare their findings.)
📝 (会議室には「サプライヤー品質報告書」が表示されており、主要サプライヤーの原材料における欠陥率の増加が示されている。CEOは苛立った表情で報告を確認しながら、品質保証部長、調達部長、工場長が対応策を準備している。)


🔹 Opening Discussion | 会議の開始

🧑‍💼 CEO:
“We’ve seen a significant increase in defects in materials from Supplier X. What’s going on?”
「サプライヤーXからの原材料に欠陥が急増しています。何が起こっているのですか?」

📋 Quality Assurance Manager:
“過去3か月で、サプライヤーXの不良率が8%から19%に増加しました。”
(In the past three months, defect rates from Supplier X have increased from 8% to 19%.)

📦 Procurement Manager:
“契約上、サプライヤーXは品質維持の責任を負っていますが、最近の納品品質は基準を満たしていません。”
(Supplier X is contractually responsible for maintaining quality, but their recent deliveries have not met standards.)

🏭 Factory Manager:
“この欠陥が生産ラインの停止につながっており、納期に影響が出ています。”
(These defects have led to production line stoppages, affecting delivery schedules.)


🔹 Investigating the Root Cause | 根本原因の調査

🧑‍💼 CEO:
“Has the supplier provided any explanation for the decline in quality?”
「サプライヤーから品質低下の理由について何か説明はありましたか?」

📦 Procurement Manager:
“サプライヤー側は、新しい生産プロセスを導入した影響だと説明しています。”
(The supplier claims that the issue is due to changes in their production process.)

📋 Quality Assurance Manager:
“しかし、変更があった場合でも、事前通知なしで品質が低下するのは問題です。”
(However, even with process changes, a drop in quality without prior notice is unacceptable.)

🏭 Factory Manager:
“特に金属部品の精度が低く、加工時の不良が増えています。”
(In particular, the precision of metal components has decreased, leading to more machining defects.)


🔹 Supplier Negotiation & Corrective Actions | サプライヤー交渉と是正措置

🧑‍💼 CEO:
“What are our options? Can we enforce contract terms or switch suppliers?”
「どのような対応が可能ですか?契約上の措置を講じるか、サプライヤー変更は可能ですか?」

📦 Procurement Manager:
“契約上、サプライヤーXには品質改善の義務があります。改善が見られなければ、契約を見直すことも可能です。”
(Supplier X is contractually obligated to improve quality. If there is no improvement, we can review the contract.)

📋 Quality Assurance Manager:
“サプライヤーとの協議を行い、品質基準を厳格に守るよう要求するべきです。”
(We should hold a meeting with the supplier and demand stricter adherence to quality standards.)

🏭 Factory Manager:
“短期的には、受け入れ検査を強化し、欠陥品の流出を防ぐ必要があります。”
(In the short term, we need to strengthen incoming inspections to prevent defective materials from entering production.)


🔹 Decision & Next Steps | 決定と今後の対応

🧑‍💼 CEO:
“Schedule an urgent meeting with Supplier X. If they don’t resolve this, we will explore alternative suppliers.”
「サプライヤーXとの緊急会議を設定してください。解決が見られない場合は、代替サプライヤーの検討を進めます。」

📦 Procurement Manager:
“すぐに会議の調整を行います。”
(We will arrange the meeting immediately.)

📋 Quality Assurance Manager:
“品質基準の厳格な適用を求める文書を作成します。📋”
(We will draft a formal request enforcing stricter quality standards. 📋)

🏭 Factory Manager:
“影響を最小限に抑えるため、追加の検査を実施します。💪”
(We will implement additional inspections to minimize disruptions. 💪)


(The meeting concludes as the team prepares to confront the supplier and enforce quality standards.)
(会議は終了し、チームはサプライヤーとの協議と品質基準の強化に向けた準備を進める。)

Practice Scenario 2.2 – Customer Complaint

📍 Scenario: Customer Complaint Investigation | 顧客クレームの調査

🔹 Participants | 参加者

🧑‍💼 CEO (English) | CEO(英語)
📋 Quality Assurance Manager (Japanese) | 品質保証部長(日本語)
📦 Customer Service Manager (Japanese) | カスタマーサービス部長(日本語)


🏭 Scene: Executive Meeting Room – Urgent Customer Complaint Discussion | 会議室 – 顧客クレームの緊急対策会議

📝 (A tense meeting room. A “Customer Complaint Report” is displayed on the screen, highlighting a sharp increase in product defect complaints. The CEO looks concerned, while the Quality Assurance Manager and Customer Service Manager prepare their findings.)
📝 (緊張感のある会議室。スクリーンには「顧客クレーム報告書」が表示され、製品不良の苦情が急増していることが示されている。CEOは険しい表情で報告を確認し、品質保証部長とカスタマーサービス部長が対応策を準備している。)


🔹 Opening Discussion | 会議の開始

🧑‍💼 CEO:
“We’ve received a surge in customer complaints about defective products. What’s the cause?”
「製品の欠陥に関する顧客クレームが急増しています。原因は何ですか?」

📦 Customer Service Manager:
“最近、返品率が30%上昇しました。主な問題は部品の欠陥によるものです。”
(Recently, the return rate has increased by 30%. The main issue appears to be defective components.)

📋 Quality Assurance Manager:
“検査データを確認したところ、一部の製品で品質基準を満たしていないものが見つかりました。”
(Upon reviewing inspection data, we found some products that did not meet quality standards.)


🔹 Investigating the Root Cause | 根本原因の調査

🧑‍💼 CEO:
“Which product lines are affected, and how did these defects go unnoticed?”
「どの製品ラインが影響を受けており、なぜこの欠陥が見逃されたのですか?」

📋 Quality Assurance Manager:
“主にAラインとBラインの製品です。検査の頻度が十分ではなかった可能性があります。”
(Primarily products from Line A and Line B. It’s possible that inspection frequency was insufficient.)

📦 Customer Service Manager:
“クレームの多くは納品後1週間以内に発生しており、問題の特定が急がれます。”
(Most complaints occur within a week of delivery, so identifying the issue quickly is crucial.)


🔹 Corrective Actions & Preventive Measures | 是正措置と予防策

🧑‍💼 CEO:
“How do we fix this immediately, and how do we prevent it from happening again?”
「この問題を直ちに修正する方法と、今後の再発防止策は?」

📋 Quality Assurance Manager:
“すぐに検査強化を実施し、不良率の高い製品は追加検査を行います。”
(We will immediately strengthen inspections and conduct additional checks on high-defect products.)

📦 Customer Service Manager:
“顧客対応の改善も必要です。影響を受けた顧客に迅速な対応を行います。”
(We also need to improve customer response. We will ensure quick resolutions for affected customers.)


🔹 Decision & Next Steps | 決定と今後の対応

🧑‍💼 CEO:
“I want a full defect analysis within a week and a new quality control protocol implemented immediately.”
「1週間以内に詳細な欠陥分析を提出し、新しい品質管理プロトコルを直ちに実施してください。」

📋 Quality Assurance Manager:
“品質管理プロセスを見直し、今後の防止策を強化します!📋”
(We will review our quality control processes and strengthen preventive measures! 📋)

📦 Customer Service Manager:
“顧客満足度を回復するため、迅速な対応を行います。📦”
(We will take immediate action to restore customer satisfaction. 📦)


(The meeting concludes as teams rush to resolve the defect issue and prevent future complaints.)
(会議は終了し、チームは欠陥問題の解決と今後のクレーム防止に向けて迅速に対応を進める。)

Root Cause Analysis

Root Cause Analysis (RCA) is a systematic method used to identify the underlying causes of problems or defects in order to implement effective solutions. In lean manufacturing, RCA is essential for continuous improvement and waste reduction. By identifying and addressing root causes rather than just treating symptoms, organizations can prevent problems from recurring and improve overall process efficiency.

Steps of RCA

  1. Define the Problem: Clearly describe the issue, including its impact on the process and any relevant details. This step ensures that everyone understands what is being analyzed.
  2. Gather Data: Collect information about the problem, including when and where it occurs, its frequency, and any patterns or trends. Data can come from production records, observations, and employee input.
  3. Identify Possible Causes: Brainstorm potential causes of the problem. Engage team members from different areas to get a comprehensive perspective.
  4. Analyze Causes: Use various tools and techniques to dig deeper into the possible causes and identify the root cause(s).
  5. Implement Solutions: Develop and implement corrective actions that address the root cause(s).
  6. Monitor and Verify: Check the effectiveness of the solutions. Ensure that the problem has been resolved and does not recur.

Tools and Techniques

  1. 5 Whys: This technique involves repeatedly asking “Why?” to drill down into the cause of a problem. Typically, asking “Why?” five times is sufficient to reach the root cause.
    • Example:
      • Problem: The machine stopped working.
      • Why? Because it overheated.
      • Why? Because the cooling system failed.
      • Why? Because the coolant level was low.
      • Why? Because there was a leak in the coolant line.
      • Why? Because the line was not maintained properly.
  2. Fishbone Diagram (Ishikawa Diagram): This tool helps identify potential causes of a problem and organizes them into categories such as People, Process, Equipment, Materials, Environment, and Management. It visually maps out all possible causes and their relationships to the problem.
    • Example: A fishbone diagram for a quality defect in a product might show causes under categories like Machine (e.g., machine calibration), Method (e.g., incorrect procedure), Material (e.g., substandard materials), and Manpower (e.g., insufficient training).
  3. Pareto Analysis: This technique uses the Pareto Principle (80/20 rule) to identify the most significant factors contributing to a problem. By focusing on the vital few causes that account for the majority of issues, you can make more impactful improvements.
    • Example: If 80% of defects are caused by 20% of the possible causes, focus on addressing these key causes first.
  4. Failure Mode and Effects Analysis (FMEA): This is a systematic method for evaluating processes to identify where and how they might fail and assessing the relative impact of different failures. It helps prioritize which issues to address based on their severity, occurrence, and detection.

Benefits in Lean Manufacturing

  1. Prevents Recurrence: By addressing the root cause, you can implement solutions that prevent the problem from happening again.
  2. Reduces Waste: RCA helps eliminate waste associated with recurring issues, such as rework, scrap, and downtime.
  3. Improves Quality: Identifying and resolving the root causes of defects leads to higher-quality products and processes.
  4. Enhances Efficiency: Solving underlying issues improves overall process efficiency and productivity.
  5. Empowers Employees: Involving employees in RCA encourages a culture of continuous improvement and ownership of processes.

Implementation

  1. Train Employees: Ensure that all employees understand RCA techniques and their importance in problem-solving and continuous improvement.
  2. Create a Standard Procedure: Develop a standardized approach for conducting RCA, including templates and guidelines.
  3. Encourage Team Collaboration: Foster cross-functional teams to bring diverse perspectives and expertise to the problem-solving process.
  4. Document and Share Findings: Keep detailed records of RCA activities and share findings across the organization to promote learning and prevent similar issues in other areas.
  5. Follow-up: Regularly review the effectiveness of implemented solutions and make adjustments as needed to ensure long-term success.

By integrating root cause analysis into lean manufacturing practices, organizations can systematically eliminate the sources of problems, leading to more stable and efficient processes, higher quality products, and a culture of continuous improvement.