2.13 Design for Manufacture and Project Management Flashcards
Critical path analysis (CPA)
- A project management method used to schedule efficient completion of process stages
- A sequential order of tasks is established for a project or process
- Unnecessary waiting time can be identified
- Parallel processing opportunities can then be exploited for maximum efficiency
Total Quality Management (TQM)
Aims to remove waste and make products right first time by continuous improvement - responsibility/involvement of all members of the workforce
Improves QA by harnessing workforce expertise
Worker’s views, feedback, teamwork and communication are highly prioritised
Scrum (agile manufacture)
- The use of workforce teams to respond quickly to issues in product design and manufacture
- Involves working in a team to reach goals in short timescale ‘sprints’
- Team goals are specified and individuals feed back progress at daily update meetings
- this meeting regularity ensures quick responses to issues
Six Sigma
System for process improvements to reduce defers to fewer than 3.4 in every million
Procedure monitors, assesses and improves each stage of design and manufacture
Five key stages (DMAIC):
Define the issue requiring improvement
Measure the extent of the issue
Analyse where the measures issues occur
Improve by introducing rectification procedures
Control the modified procedures through effective QA
Quality control (QC)
Monitoring, checking and testing procedures used throughout production
using tests at every stage of production to ensure the product is the correct size, shape and surface finish
After manufacture the product is tested to ensure it functions correctly
Involves inspections
Visual aesthetic checks
Dimension and machine tool checks using vernier callipers (+- 0.02mm) and micrometers (+- 0.01mm)
Check of component fit and quality of finish
Quality assurance (QA)
Procedures and policies which ensure that products meet specification criteria
Example policies and procedures:
FEA and MFA (mould flow analysis - predicts material flow in mould)
Identification marks for tracing faults
CAD modelling to check fit and assembly
Maintenance of machines to maintain tolerances
Materials and components from ISO 9001 Quality Management suppliers
Checking temperatures for effective cavity filling
Monitoring, checking and testing for QC
Simple visual checks
Chemical analysis of samples (e.g. Moisture content or chemical composition)
Colour matching for pigments or paints
Use of digital measuring devices such as micrometers and vernier callipers
Go/no go gauges
QC check
Check a single measurement for tolerance range with a pass/fail reading
Made with minimum and maximum dimensions so it easy to use
Quicker than digital measuring devices as no readings need to be taken
No need for adjustment or recalibration
Laser or probe scanning and measuring
Coordinate measuring machinery (CMM)
Prove scanners can check predefined measurements or finished components
Highly accurate, with automatic comparison with 3D CAD model
Non-contact lasers can scan thousands of readings per second for greater accuracy
Also used to check tooling accuracy for QA tool change procedures
Project management methods
Six Sigma
QA and QC
Scrum (agile manufacture)
CPA
TQM
Accuracy in small-scale production
Slight inaccuracies may add to the bespoke nature of the product
Attention to detail, traditional tools and hand craftsmanship mean that highly skilled workers are required to achieve good accuracy
Use of measuring devices such as calipers and gauges
Possible use of templates
Accuracy in medium scale production
Extensive use of jigs and fixtures for consistency within the batch
Often utilises highly accurate CNC
Use of sophisticated measuring devices
Monitoring to maintain a right first time approach
Accuracy in large scale production
Sample testing during and after manufacture
Constant monitoring for right first time
Effective machine tool maintenance, replacement and alignment procedures are required
A mould replacement cycle needed to deal with wear from heavy usage
Addressing legislation compliance
Use of computerised measuring equipment and go/no go gauges for fast and easy checking of measurements
