Project Quality Management Quality Management Quality and quality

Project & Quality Management

Quality Management • Quality and quality attributes • Quality problem-solving tools • Product life cycle • Quality and cost • Reliability

What is Quality • ‘Conformance to specification’ • ‘Fitness for purpose’ • ‘Meeting customers requirements’ • ‘Doing things right first time’ • The features and characteristics of a product or service which bear upon its ability to satisfy a stated need’ (BS 4778)

What is Quality Nine Quality Dimensions • Performance • Serviceability • Features • Aesthetics • Reliability • Safety • Conformance • Perceived quality • Durability

Quality Dimensions Performance – A product’s primary operating characteristics Features – Additional items to the basic specifications Reliability – The probability a product operates correctly for a given time frame under specified conditions

Quality Dimensions Conformance – How well physical and performance characteristics meet established standards Durability – How long the product lasts before it needs to be replaced Serviceability – The ease of getting a product serviced or repaired. After sales service.

Quality Dimensions Aesthetics – How well the product looks, feels, smells or tastes Safety – Assurance that the customer will not be injured or hurt when using the product Perceived Quality – Subjective assessment based on image, advertising or brand names.

What is Quality Different meaning: • • Designer – features, safety Manufacturer - conformance Distributor - perceived quality, serviceability Customer - reliability, aesthetics, safety

Managing Quality Define User Requirements what the person using the product needs Product Characteristics product specification used by the manufacturer Measurable Quality Attributes a characteristic that is either present or absent in the product and can be measured

Example – Mobile Phone User Requirements: Portable, Appearance, Calls, Texts, Pictures, etc. Product Characteristics: Weight, Shape, Colour, Screen/picture resolution, memory etc. Quality Attributes: Exact weight, pixels, size of memory, wireless range etc.

Quality Attributes Characteristics measured to control the quality of the product. Once defined, the manufacturing processes needed to achieve them and the means to measure them can be determined.

Example - Drink Bottle Customer requirements Product characteristics Quality Attributes Manufacturing processes

Customer requirements - Bottle

Customer requirements - Bottle REQUIREMENTS Easy to hold Easy to Open Leak-proof Non-Toxic CHARACTERISTICS Weigh less than 100 g Screw on cap Rubber seal Food grade plastic

Customer requirements - Bottle ATTRIBUTES Wall Thickness Thread geometry Thickness of seal Type of plastic PROCESSES Mould Dimensions Shot Weight Material Spec Mould Temperature Cooling time Assembly method etc.

Problem Solving Tools – Why? Ideal quality attribute not always achievable in practice. Quality management strives to improve the process by all means possible: → collecting data → analysing data → suggesting ways to improve it

Problem Solving Tools • Used to identify underlying trends in data that are not readily apparent otherwise • Used to suggest solutions • Emphasis is on Systematically describing the process and its problems • Used as part of a PDSA cycle.

PDSA Cycle • Deming Cycle Plan – Do – Study – Act

Deming Cycle Plan • • Analyse current situation Gather data Use problem solving tools to unravel problem Suggest solution Do • • Put trial or pilot solution in place Usually on some small part of the process

Deming Cycle Study • • Critically evaluate trial solution Examine problems or opportunities Act • Implement solution in a standardised manner: Ø Formally adopt as standard procedure Ø Fully document • Begin next cycle of PDSA

Problem Solving Tools • Flow charts • Bar Chart • Cause and effect diagrams • Scatter diagrams

Flow Charts Purpose: • • describes the process to which the problem belongs Understand all the stages of the process and how they relate to one another Helps to: • • • Eliminate duplicate or unnecessary steps Identify critical areas Identify areas that need improvement

Example: PCB Project

Checksheet Tally Charts • Simple method of gathering data • Useful when a lot of data needs to be gathered quickly by observation • Can be used to show cumulative list of problem areas

Checksheet Tally Chart of problems in PCB project Problem by category Total Dry joint 1111 1111 1 33 Over solder 1111 1111 11 26 1111 1111 1 21 1111 8 1111 4 111 3 11 2 Not soldered Incorrect placement Faulty component Tracks Damaged on PCB Design error in circuit Heat damage to component

Bar Chart • Useful for showing distribution of data e. g. sizes of a manufactured component. • Can be used to pinpoint causes of error

Two Machines Making the Same Part Target size 20 mm Measured sizes distributed around this value Machine B: approx same distribution but centred around 20. 2 mm Suggests tool setting error

Cause and Effect Diagram • Used to identify causes of problem • Sometimes called ‘fishbone’ diagram

Cause and Effect Analysis Causes usually attributed to: • • Materials Machinery Methods People 3 Ms and P

Case study: Soldering Problems

Soldering Problems – more detail

Soldering Problems – third pass

Scatter Diagrams Useful for establishing (or dispelling) a causal link between two factors Possible outcomes are: • • Positive correlation Negative correlation Weak correlation No correlation

Scatter Diagrams Positive Correlation ‘y’ increases as ‘x’ increases

Scatter Diagrams Negative Correlation ‘y’ decreases as ‘x’ increases

Scatter Diagrams Weak Correlation Another factor may be the cause of the problem.

Scatter Diagrams No Correlation Random arrangement of plotted points. No relationship between ‘x’ and ‘y’.

Example: Small drills used to drill PCBs in a Technology project Increasing drill size: • • Reduces breakages Reduces time taken to drill hole • Increases likelihood of bad joint

Data: Drill Dia No. bad Joints Time taken per hole No. Drills Broken 0. 8 0. 9 1. 0 1. 2 6 7 12 15 30 sec 25 sec 10 sec 7 6 5 5

Plots

Plots What the optimum size drill to use? Compromise will be involved No ‘right’ answer

Degradation of Quality Attributes Product characteristics: • Waterproof • Resistant to corrosion Pond Alarm Unit Quality attributes: • Effectiveness of seal between casing and lid • Corrosion resistance of material

Degradation of Quality Attributes Ideal situation: Unit completely waterproof and Corrosion resistant. Design stage – student choices made re: materials and manufacturing processes Cover – plastic on a CNC router Casing – tinplate and soldered

Degradation of Quality Attributes Degradation factors: • how accurately the parts are manufactured • tolerance achieved • bending the tinplate • soldering technique • flux may cause some surface corrosion

Degradation of Quality Attributes Compromise: • function satisfactorily in the rain but not when submerged • last a specified number of years

The Cost of Quality costs money • • • Time Resources People

The Cost of Quality Two costs associated with quality: 1. Cost of conformance • • Putting measures in place Running quality system 2. Cost of non-conformance • • • Errors Waste Warranty claims etc.

The Cost of Quality Total cost of non-conformance Cost of non-conformances Total cost of conformance Warranty claims Rejects & Scrap Errors & Waste Poor Service/Delivery Loss of Customers etc Cost of conformance Cost of non-conformance Quality systems Process control Reliability etc Cost of non-conformance > cost of conformance

Product Life Cycle – 4 Stages Introductory • Product expensive • Recover cost of development • Minimal profits • People not aware of product Growth • Product is successful • Adopted by mass market • Still expensive • Strong demand

Product Life Cycle – 4 Stages Maturity • Sales and profits stabilise • Competing products enter market • Prices fall Decline • Sales and profit decrease

Product Life Cycle Sales Profit

Quality and Market Share The quality of the product plays a large part in its market share. Premium-quality products usually: • • • have large market shares are early entrants to their markets. charge premium prices for their product.

Quality and Market Share • Quality improvement can reduce profitability, i. e. the amount of profit per product, due to increased costs. • The increase in market share will normally cancel out the extra cost involved

Quality, Market Share and Costs Improved quality of design Higher Perceived value Increased market share Improved quality of conformance Higher prices Increased revenues Higher profitability Lower manufacturing and service costs

Simple statistical measures Useful and common methods of measuring the central tendency of a variable: • The Mode • The Median • The Mean

Simple statistical measures Mode Is the most common value from a group. The following are drill sizes in mm 2 2 3 3 3 4 4 5 The mode is 4 mm which is the most common value, appearing on four occasions

Simple statistical measures Median Is the middle value when all outputs are arranged in numerical order. 22 3 3 3 4 4 5 In the example above, the middle values are 3 mm and 4 mm, so the median would be 3. 5 mm, halfway between 3 mm and

Simple statistical measures Mean Is the average value represented by the following equation:

Classification of Quality Costs • Prevention costs • • Planning & operation of a quality system Appraisal costs • • Monitoring & inspecting the product Internal Failure costs • • Failure costs associated with non-conformance. Detected before it leaves factory External Failure costs • Cost of non-conformance after delivery

Example: Quality Costs

Classification of Quality Costs Cost PCB Prevention Costs Practice of correct soldering technique Learn to use PCB and circuit design software 1 Day Housing Cost Prevention Costs Set up gauge blocks to measure casing opening. Correct tolerance of mating parts 1 hour 2 hours Appraisal costs 1 hour Inspection of solder joints ½ hour Check component placement 1 hour against drawing Simulation of circuit Appraisal Measure and inspect before assembly ½ hour Internal Failure Replacement IC Replacement PCB Rework time € 5 € 1 1 Day Internal Failure Rework Scrap material 2 Days € 5 External Failure Loss of marks ?