Quality Management Systems & Production Control

Posted on Jun 5, 2025 in Other subjects

Process Improvement & Quality Management Fundamentals

Quality Management is a set of coordinated activities to direct and control an organization to meet customers’ requirements and improve the effectiveness and efficiency of its performance.

Schools of Quality Management

The evolution of quality management systems has led to distinct schools of thought:

Total Quality Management (TQM)

Focuses on strategic impact and market needs, with all members of the organization responsible for quality.
Emphasizes strategic planning, goal setting, and top management’s leadership.
Quality professionals lead training, goal setting, and cross-departmental collaboration.

Quality Assurance & QMS

Focuses on the coordination of the entire production chain and the contribution of all groups to proactively prevent quality failures through programs and systems.
Responsibility for quality is distributed among all departments, with top management participating peripherally in the design, planning, and execution of quality policies.

Quality Control Principles

Focuses on controlling product uniformity using statistical tools and techniques, with minimal inspection.
Views quality as a problem to be solved, and the manufacturing and engineering departments are responsible for applying statistical methods and problem-solving.

Quality Inspection Methods

Aims to identify defects and ensure product uniformity through calibration and measurement.
Views quality as a problem to be solved, with the inspection department handling sorting, counting, and grading.
Philosophy: Good quality can be achieved through inspection of the product.

Core Principles of TQM

1. Customer Focus

Organizations depend on their customers and must understand their needs and requirements. It is more costly to attract a new customer than to retain an existing satisfied one. Therefore, it is essential to keep customers happy.

To ensure satisfaction, customer needs and expectations must be identified and communicated. The most critical aspect is listening to the customer. It’s important to continuously monitor customer needs to maintain satisfaction.

The goal is to consistently meet customer expectations and provide value.

Internal vs. External Customers:

Output: The specific products or services produced as part of a work process.
Internal Customer: Uses the output as an input in their own work process.
External Customer: The final user of the product or service.

Customer Requirements:

Unspoken (Level 1): Basic requirements that are assumed.
Expressed (Level 2): Specific specifications and needs that customers articulate.
Latent (Level 3): Requirements that customers don’t expect but add significant value when provided.

2. Process Improvement

Desired results are achieved more effectively when resources and activities are managed as a process.

Aims of Process Improvement:

Create reliable processes that deliver desired results consistently.
Redesign processes to achieve superior outcomes.

Process: A sequential integration of people, materials, methods, and machines to produce value-added outputs for customers.

Key Stakeholders in Processes:

Customers: Individuals or entities for whom the output is produced.
Workgroup: Individuals who produce and deliver the output.
Supplier: Individuals or entities who provide the input.
Owner: The person responsible for the process’s operation and improvement.

Process Classification:

Management Processes: Related to the organization’s governance and strategic direction.
Main Processes: Create core value (e.g., Manufacturing, Product Development).
Supporting Processes: Support the main processes (e.g., IT, HR).
Key Processes: Critically affect success and are company-specific.

3. Total Involvement

Leaders establish purpose, direction, and the internal environment, fully engaging people to achieve organizational objectives.

The key difference between average and outstanding companies lies in leadership.

People are the essence of the organization, and their involvement maximizes the use of knowledge and experience for the organization’s benefit.

Employees are considered a company’s greatest asset, and quality originates from the hearts and minds of its people.

Autonomy: Focuses on aligning performance and building trust to achieve optimal performance by providing the right materials, methods, and skills.

Empowerment Dimensions:

Alignment: Knowledge and support of the organization’s vision, values, and objectives, which builds motivation.
Mutual Trust: Employees must trust management and feel trusted by them for empowerment to be effective.

Empowerment Matrix

Supporting Elements for TQM Implementation

Leadership: The crucial role of senior managers.
Education and Training: Quality is based on the skills of every employee and their understanding of what is required.
Supportive Structure: Senior management may need support to make the changes necessary to implement a quality strategy.
Communication: Transmit to all employees a real commitment to change to overcome resistance. Encourage bottom-up flow of information.
Reward and Recognition: Teams and individuals who apply the quality process need to be recognized and rewarded (e.g., through examples and role models).
Measurement: Use of data for establishing and improving a quality management process.

Quality Management Standards (QMS)

Understanding Quality Management Systems

A Quality Management System (QMS) comprises an organization’s policies, procedures, resources, and processes aimed at achieving outcome quality levels aligned with customer specifications and the company’s objectives.

It is a system standard, NOT a product standard.
The standard sets general requirements.
Certification is often pursued.

ISO 9000 Series Standards

The ISO 9000 series is the best-known QMS standard. It provides technical specifications and criteria to be used as rules to ensure that materials, products, services, and processes are fit for their purpose.

Designed as a minimum quality standard, it does not specify how the requirements are to be implemented.

Highest quality is achieved through a combination of technical product specifications and management system standards.

Specific ISO 9000 Standards:

ISO 9000:2015 – Fundamentals and vocabulary (provides information and definitions).
ISO 9001:2015 – Requirements (specifies basic QMS requirements).
ISO 9004:2018 – Guidance to achieve sustained success (focuses on improving QMS performance).

ISO 9001 Implementation Logic:

The standard specifies the issues to be regulated.
Define and document rules for internal operations.
Apply these internal rules.

Auditors verify compliance between these phases.

Key Principles of ISO 9001

Customer Focus
Leadership
Process Approach
Improvement
Engagement of People
Evidence-based Decision Making
Relationship Management

Quality Management System Auditing

Auditing is a systematic checking method to verify how the company meets the standard.

Types of QMS Audits:

1st Party: Internal audit, conducted by the company to prepare for the system.
2nd Party: Supplier or customer audit, conducted to check customer’s needs.
3rd Party: Independent, external audit, conducted by an independent company leading to certification.
- Third-party certification is usually required every three years and can provide a competitive advantage.

QMS Documentation Requirements

QUALITY MANUAL: Defines how the QMS operates.
QUALITY PROCEDURES: Define who, what, and when.
JOB INSTRUCTIONS: Answer how tasks are performed.
QUALITY RECORDS, REPORTS: Demonstrate that the system is operating effectively.

Quality Management Tools & Methods

Essential Quality Tools

Flowcharting for Process Description

A Flowchart is a tool to describe processes.

Identifies participants, their roles, and process steps.
Identifies inefficient and wasteful steps.
Offers a framework for defining process measurements.

Flowchart Symbols:

Oval: Process start/end
Rectangle: Activity
Diamond: Decision
Arrow: Process direction

Steps to Create a Flowchart:

Define process boundaries.
Define process steps.
Draw the flowchart.
Check its completeness.
Evaluate the process.

Types of Flowcharts:

High-level: Provides a general overview of the process, composed of main activities.
Detailed: Includes all activities and decision points.

Idea Collection & Teamwork Techniques

Teamwork
Creativity
Brainstorming, Affinity Chart (for idea collection and categorization, can be time-consuming).

Problem Solving for Process Improvement

Used for process improvement and failure analysis.

Ishikawa Diagram (Fishbone Diagram): Identifies and represents all possible causes of a problem to discover its root causes.
5 Whys: A technique to reach the root cause by repeatedly asking ‘why’ (typically five times).
ABC Analysis Diagram: A formal statistical technique.
- Errors are grouped into three categories:
  - A: Critical errors that have the most significant impact.
  - B: Errors that could become critical.
  - C: Errors with minimal impact.
- Bar graph: Bar’s length represents frequency or cost, with the longest bars typically on the left.
- The diagram visually highlights the most important problems.

Quality Management & Risk Assessment

Risk: The effect of uncertainty, which can have positive or negative impacts.

Negative effects are considered risks.
Positive effects are considered opportunities.

Risk Management Methods

Failure Mode and Effects Analysis (FMEA)

FMEA: Seeks to eliminate errors, increase reliability, and analyze risk.

Design FMEA (DFMEA)
Process FMEA (PFMEA)

FMEA Implementation Steps:

Planning
System Analysis
Function Analysis
Failure Analysis: Collect all potential risks.
Risk Analysis

FMEA Risk Factors:

Severity (S): The effect of the failure (1: not visible, 10: catastrophic, e.g., fatality). Occurrence (O): The likelihood of the failure occurring, considering the efficiency of preventive actions (1: 100% preventive, 10: highly likely). Detection (D): The efficiency of the checking method in detecting the failure (1: 100% detected, 10: not detectable).

FMEA Risk Measurement:

RPN (Risk Priority Number) = S * O * D. Ranges from 1-1000. Companies often set an acceptable RPN limit. AP (Action Priority): Categorized as H (High Risk), M (Medium Risk), L (Low Risk). Optimization Documentation: Includes promotions and determination of deadlines.

Additional Quality Management Methodologies

Complaint: Feedback received when a product or service does not meet specifications.

The 8D Problem Solving Report

Complaint Information: Gather information from the customer.
Establish the Team: Form a cross-functional team.
Describe the Problem: Clearly define the problem.
Implement Immediate Containment Actions: Identify actions to protect the customer.
Determine Root Causes: Utilize problem-solving tools.

Ishikawa Diagram: Often used for manufacturing issues.
5 Whys: Often used for software-related issues.

Develop Long-Term Corrective Actions:

Root Causes: Address occurrence (why it happened), detection (why it wasn’t detected), and systemic (why we couldn’t prevent it).
Actions are developed based on the 5 Whys analysis.

Implement Long-Term Corrective Actions: Execute and monitor the actions. Define Preventive Actions: Identify actions to eliminate or prevent recurrence of similar issues.

Examples include checking similar processes, FMEA review, and lessons learned.

Congratulate the Team: Finalize the 8D report, review, and close the issue.

The 5S Methodology

5S: A Japanese methodology to analyze the quality of work and its culture.

5S Steps:

Sort (Seleccionar)
Set in Order (Ordenar)
Shine (Limpiar)
Standardize (Estandarizar)
Sustain (Mantener)

Poka-Yoke (Mistake-Proofing)

POKA-YOKE: A Japanese method to prevent or avoid human errors (mistake-proofing).

Control Plan & SPC

CONTROL PLAN: Provides a plan for addressing nonconformities, often utilizing Statistical Process Control (SPC).

Statistical Process Control (SPC)

SPC Methods

Control Charts: For detecting problems in the process.
Process Capability Indices: Evaluate a process’s ability to meet customer requirements, assess performance, and predict the number of defective items.

Common Causes: Small, unavoidable causes inherent to the process (e.g., minor temperature fluctuations).

Special Causes: Out-of-control causes, occasionally present and assignable (e.g., equipment malfunction).

Control Charts for Process Monitoring

Objective: To distinguish between common and special causes and prevent the production of flawed items.

m samples of size n.
R-chart: Monitors the process variation (R: Range = max-min).
X-bar chart: Monitors the process average (X: Mean).

Control Chart Performance & Errors

Due to sampling error.

Type I Error (Alpha Risk): Occurs when an in-control process is mistakenly considered out-of-control, leading to unnecessary adjustments.
Type II Error (Beta Risk): Occurs when an out-of-control process is mistakenly considered in-control, failing to detect a process shift.

Control Chart Application Phases

Phase I: Retrospective analysis, ensuring the process is stable and predictable.
Phase II: Ongoing process monitoring.

Measurement System Analysis (MSA)

A measurement system refers to the entire set of elements involved in the measurement process.

Factors Influencing Measurements:

Resolution: The smallest difference that the measurement system can detect.
Display Resolution: The smallest difference that the measuring device can display.
Accuracy: The closeness of the mean value of measurements to the true value.
Stability: The consistency of measurements over time when measuring the same characteristic.
Repeatability: The variation in measurements obtained with one measuring instrument when used multiple times by one appraiser while measuring the same characteristic on the same part.
Reproducibility: The variation in the average of measurements made by different appraisers using the same measuring instrument when measuring the same characteristic on the same part.

MSA Evaluation Criteria:

R&R > 30%: Not acceptable – Indicates too much variation, leading to unreliable results.
10% < R&R < 30%: Partially acceptable – The measurement system is partially acceptable, but improvement is recommended.
R&R < 10%: Acceptable – The measurement system is reliable.

Lean Principles & Process Assessment

Process Assessment in Quality Management

A method for measuring process capability by comparing it with best practices and identifying risks. The goal is to improve long-term efficiency and product quality.

Process Assessment vs. Audit: Key Differences

Process Assessment: Focuses on product development and analyzes development processes in detail. Assessment is typically according to Capability Levels (CLs), with no formal certificate and variable target areas.
Audit: Focuses on the entire company, with the goal of a general overview. A certificate is typically issued (and can be failed), and the target area is usually predefined.

Lean Methodology for Continuous Improvement

Lean: Seeks to eliminate waste, creating an environment of continuous improvement, motivating measurable and sustainable changes.

Lean vs. Six Sigma: Core Objectives

Lean: Aims for efficiency improvement.
Six Sigma: Aims for quality improvement.

The Seven Wastes of Lean (Muda)

Overproduction: Producing more than demanded by the client or standard requirements.
Inventory: Excess raw material, Work-In-Process (WIP), or finished product that is stored.
Waiting: People or parts waiting for a work cycle to be completed.
Motion: Unnecessary movement of people within a process.
Transportation: Unnecessary movement of parts within the process.
Rework/Defects: Defects, repetition, or correction of a process.
Overprocessing: Performing more work than required by the client, or processing before it’s needed.
Wasted Potential of People (Talent): Underutilization of employee skills, knowledge, and creativity.

Production Management & Inventory Control

Key Production Operation Measures

Evaluate decisions related to production management.

Production Rate: Number of products made in a given period.
Amount of Inventories.
Direct Operation Costs (excluding marketing).

Resource Capacity Planning

Resource Capacity: The amount of products or services that can be produced in a given time.

Design Capacity: Maximum output under ideal conditions.
Effective Capacity: Maximum output under actual operating schedules.
Capacity Utilization: Proportion of design capacity currently being used.
Efficiency: Proportion of effective capacity used under normal operating conditions.

Demand Management Strategies

Demand Management: Redirects demand from periods of capacity shortage to periods of spare capacity.

Strategies include changing price, producing stock, adjusting order lead time, and managing order intake.

Capacity Management Adjustments

Capacity Management: Involves adjusting factors in the Effective Capacity (EF) formula.

Leasing equipment (resources).
Increasing number of shifts (shifts/day).
Working overtime (days, hours).
Rescheduling maintenance.
Making customers perform certain operations (saving time).

Short-Term Capacity Planning

Short-Term Capacity Planning: Effective capacity must be higher than the required task (Q).

Inventory Management Fundamentals

Inventories: Supply of goods and materials (Raw Materials (RM), Work-In-Process (WIP), finished goods).

Benefits of Holding Inventory:

Stabilize and smooth workflows.
Protection against shutdowns, delays, and uncertain demand.
Taking advantage of price discounts on large orders.

Drawbacks: Inventory Costs

Inventory Control Strategies

Inventory Control: The effort to maintain inventory levels and costs within acceptable limits.

How to Order?

Continuous Review System: Inventory level is monitored continuously, and an order is placed when it drops to a specified reorder point.
- More flexible to changes in demand (less risk of stockouts).
- Requires checking inventory level each time an item is removed.
Periodic Review System: Orders are placed at regular intervals to raise the inventory level to a specified target.
- Easier to organize.

How Much to Order?

Economic Order Quantity (EOQ): Determines the optimal order quantity to minimize total inventory costs.
- Assumptions: Lead time = 0, demand is known and constant, no shortages, ordering and setup costs are constant, holding costs are proportional to unit costs.
- Large, infrequent orders have high holding costs but low ordering costs.
- The sum of these costs forms a U-shaped curve, with the minimum point indicating the optimal order size.

When to Order?

Costs Associated with Inventory

Unit Purchasing Cost: Price of a product or cost of manufacturing.
Order Cost: Cost associated with placing an order.
Unit Holding Cost: Cost of holding one unit of an item in stock for a unit period.
Shortage Cost: Occurs when an item is needed but cannot be supplied (cost of stockout).

Lead Time in Inventory Management

Lead Time: The duration you have to wait before new stock arrives.

Lead Time Scenarios:

Order arrives in the same cycle (Lead Time < Cycle Time).
Order arrives in a subsequent cycle (Lead Time > Cycle Time).