Quality Assurance And Quality Control

Question 1

What Quality Assurance (QA) and What Does It Involve

Answer 1

QA is a procedure or system which is followed in order to achieve the desired level of quality.

An effective quality assurance procedure involves:
• Measurement of variables
• Comparisons with specifications
• Constant monitoring of processes
• Using feedback loops to prevent errors

Quality assurance is process led and focuses on defect prevention

Question 2

What are the 4 Quality Assurance Systems you need to know?

Answer 2

• Total quality management (TQM)
• Scrum
• Six Sigma
• Critical path analysis (CPA)

Question 3

What 3 things do you need to know about Quality Assurance for?

Answer 3

• Waste Reduction
• Accurate Manufacturing
• Applying Tolerances

Question 4

What is a Flow Chart and what does it help with

Answer 4

A simple way to plan a sequence of manufacturing events is by using a flowchart
• A flowchart is a type of diagram that shows a workflow or process and is usually read top to bottom, left to right
• They highlight critical control points and allow feedback
• Flowcharts help manufacturers to identify possible problems such as bottlenecks

Question 5

What are Gantt Charts and What are they used for

Answer 5

Gantt charts are named after their inventor, Henry Gantt in the early 19th century. They are a widely used project management tool showing:
• the phases of a project
• individual tasks
• key milestones
• required resources
• Tasks are usually shown on the vertical axis whilst timings are recorded on the horizontal axis

Question 6

What is Total Quality Management (TQM) and what do it’s key features include

Answer 6

Based on the principals of Kaizen, Total Quality Management (TQM) is a customer focused, process centred strategy

Key features include:
• Integrated strategies and systems
• Employee involvement
• Communication
• Constant feedback
• Continuous improvement

Question 7

What is a Scrum Development Process

Answer 7

Scrum is a quality driven, agile framework for managing product development and problem solving. (Named after a rugby scrum used to restart a match)

Question 8

How does the Scrum Development Process Work (what happens)

Answer 8

Scrum is initiated by the product owner with a product backlog (a wish list of items to bring to the market).

• The scrum master leads scrum team in series of sprints (shorter focused
tasks delivered by the team)
• Scrum uses different types of sprint meetings and lists to ensure everything is
kept on track

Question 9

‘Sprint Backlog’ and ‘Scrum Board’ Definitions

Answer 9

Sprint Backlog - The sprint backlog is a list of products to produce in the next sprint

Scrum Board - The scrum board contains a list of tasks for each team member and tracks their progress

Question 10

What are the 4 Types of Meeting used to explore a Sprint

Answer 10

• Sprint planning – used to set up the sprint parameters
• Daily ‘stand-ups’ – used to check if everything is going to plan
• Sprint review – used to deliver the results and get feedback
• Sprint retrospective – used to reflect on what can be improved

Question 11

What is Six Sigma and How Does it Work?

Answer 11

Created at Motorola in 1986, Six Sigma aims to improve process and management performance.

Six Sigma projects follow a methodology inspired by W. Edward Deming’s ’Plan-Do-Study-Act’ Cycle (PDSA)

Question 12

What are the 5 Stages that make up Six Sigma

Answer 12

It comprises five phases:
• Define
• Measure
• Analyse
• Improve
• Control (DMAIC)

Question 13

What Does ‘Six Sigma’ Refer to?

Answer 13

‘Six Sigma’ refers to the number of allowable defects, 3.4 defects per million (DPM).

Identifying and removing the main causes of errors improves efficiency, productivity and quality and limits waste. (Many large corporations now use Six Sigma)

Question 14

What are the 2 main ways Businesses use Methods of planning and charting projects?

Answer 14

• Project evaluation and review techniques (PERT)
• Critical path analysis (CPA) or critical path method (CPM)

Question 15

How Do ‘Project Evaluation And Review Techniques’ (PERT) AND Critical Path Analysis/Method (CPA/CPM) work?

Answer 15

• Both PERT and CPM rely on arrow and node diagrams
• They calculate the longest path of all planned activities to their individual end points or to the end of the project
• Some tasks have float, meaning that there is room for them to be delayed without making the project longer

Question 16

What is Critical Path Analysis (CPA) and How Does It Work?

Answer 16

Critical Path Analysis is a six step method used to plan sequential activities, showing them as nodes, usually boxes joined with arrows with each box including details of the duration of each task.

• Stage 1: Specify each task
• Stage 2: Sequence activities
• Stage 3: Draw network diagram
• Stage 4: Estimate timelines
• Stage 5: Identify the critical path
• Stage 6: Update diagram to show progress

Question 17

What is Project Evaluation Review (PERT) and How Does It Work?

Answer 17

Project evaluation and review (PERT) is very similar to CPA, however it does not give a single estimate of project duration.
Instead it allows the user to calculate a realistic timescale based on three variables which can assist long term planning:

• Optimistic duration (O)
• Most likely duration (M)
• Pessimistic duration (P)

The final calculation to find the most realistic duration (E) is: E = (O + 4M + P ) ÷ 6

Question 18

What are Some Examples of Measuring Tools used for Measuring Materials Accurately

Answer 18

Measuring materials accurately requires tools with accurate reference or ‘datum’ points – surfaces or edges from which all other measurements are taken.

Measuring tools include:
• Traditional tools such as rules, squares callipers and gauges
• Digital micrometres and callipers
• Laser and probe scanners
• A dial test indictor or DTI (pictured) uses a probe to test accuracy from a specific reference point

Question 19

What is Tolerance

Answer 19

High volume production aims for absolute accuracy and efficiency but there is a small margin for error. This margin for error is called the tolerance and can apply to hole depth, length, angle, thickness, weight, elasticity and so on.

All products must be within tolerance or they will be rejected during quality control checks.

Question 20

What Tool is used to check Tolerances

Answer 20

Go-no go gauges can be used to test components to see if sizes fall within a given tolerance

Question 21

What Does Quality Control (QC) Do/Ensure

Answer 21

Quality control ensures product standards are met. Various tools are used to ensure parts have dimensional accuracy and are within tolerance.

Question 22

What are Visual Checks done for?

Answer 22

Visual checks are still used to check quality throughout the production process to ensure that:

• Supplied materials comply with the manufacturer’s requirements
• Parts and components are within tolerance
• Finished products and components match the product design specification
• Products comply with relevant standards

Question 23

What is Probe Scanning Used For?

Answer 23

Coordinate measuring machinery (CMM) is used to check the measurements of finished components

Question 24

What is Probe Scanning Able To Do?

Answer 24

Probe scanning:
• uses a calibrated probe pin and highly sensitive sensors
• tests dimensional accuracy
• can scan dynamically along a surface or measure using predetermined data points
• enables comparison of points against 3D CAD models

Question 25

What is Laser Scanning Used For?

Answer 25

Non-contact co-ordinate measuring machinery (CMM) is also used.

Question 26

What is Laser Scanning Able To Do?

Answer 26

Laser scanning:
• Uses a laser reflected off the surfaces of a product
• Can take thousands of accurate measurements very quickly
• Creates an accurate comparative 3D CAD model
• Can spot potential wear and tear in a system and accurately predict maintenance

Question 27

What is Non-Destructive Testing (and what methods are there to do it)

Answer 27

The internal structure of materials or manufactured parts can be checked using non-destructive testing (NDT) methods such as:
• Ultrasound
• X-ray analysis

These can be used to measure wall thickness and detect internal faults not visible to the naked eye

Question 28

What is the Kitemark and what is it good for?

Answer 28

The Kitemark is a UK product and service quality trade mark which is owned and operate by the British Standards Institution (BSI group). A company would put their product through lab tests, before having to pay for this trademark.

The Kitemark is most frequently used to identify products where safety is paramount, such as crash helmets, smoke alarms and flood defences.

It assures customers that the product has passed many safety tests.

Question 29

What is Critical Path Analysis and what is it used for?

Answer 29

Critical Path Analysis (CPA) is a project management method used to analyse all individual stages within a project, and to plan the effective and time efficient completion of each element within the desired schedule.

Question 30

What does Critical Path Analysis Help with?

Answer 30

Using a task analysis, the project/process can be split down and each individual element can be arranged in time order. The basic order is sequential, with each element being completed one after the other.

This method often identifies wasted time within the process, when the individual completing the process is waiting unnecessarily to complete the next task.