1. Statistical Process Control for Aerospace Manufacturing
Presented by: Ben Allister (Infodream Ltd)
Intro & presentation plan.
Intro to myself

2. Software Developer and Continuous Improvement (CI) competence centre
Introduction To Infodream
Software Developer and Continuous Improvement (CI) competence centre
Real Time QC Software
Real Time Data Collection and Process Control
Bespoke industrial software solutions
Integrated Advanced Quality Toolbox
Cont Imp. Services
Training
Strategy and implementation
On-site Mentoring & Services
Mention SPC Vision is part of Qualaxy suite which also consists of other shopfloor modules
NC management
Process planning
EN9103 KC management

3. Some of Our Clients Aerospace Nantes (FR) Saint Nazaire (FR)
Toulouse (FR)
Filton (UK)
Stade (GE)
Illescas (SP)
Marignane (FR)
La Courneuve (FR)
Filton (UK)
Méru (FR)
Conflans Ste H.
Fareham (UK)
Méaulte (FR)
Saint Nazaire (FR)
Genève (CH)
Liège (BE)
Montrichard(FR)
Niort (79)
Roche la Molière (42)
Le Havre (FR)
Toulouse (FR)
Genevilliers
Evry - Corbeil
Le Creusot
Valenciennes (FR)
Issoire (63)
Modane (73)
Toulouse (FR)

4. What is SPC
Statistical Process Control (SPC) is a continuous improvement tool
Reduce waste
Improve quality
Increase productivity
Tells us whether our processes can consistently meet the customer requirements
Identifies sources of unwanted variability in the process and helps us understand the relationship between product & process
Pro-actively monitors &controls the process to avoid defects and failures

5. A Tool for Continuous Improvement
What is SPC
A Tool for Continuous Improvement
- Using meaningful data
Statistical
- To understand a process
Process
SPC should not be about complex maths although many people like to confuse people with their super 6 sigma tools which nobody else understands.
- To make it behave the way we want
Control

6. Good Bad Understanding Variation Limit Limit
SPC is based on process variation.
Only 2 outcomes – in or out
Through the posts = 3 points
Outside the posts = nothing
But, the ball never goes through the centre every time!

7. Bad Understanding Variation Limit
There is variation in the kicking process

8. Variation Understanding Variation Limit
Variation is caused by lots of factors
Wind
kicking angle
distance
kicking ability
how much the player had to drink the night before!
Coaches will have lots of statistics to help them choose the best kicker and have the highest probability of scoring.

9. Variation Cost Understanding Variation (The Enemy) - Material Waste
Limit
Variation
Target
Cost
(The Enemy)
- Material Waste
Scrap
Repair
Ass’y Problems
Tight tolerances
Additional operations
Increased Inspection
Manufacturing process also contain variation.
But, the effect is not so straightforward or widely understood.
A famous japanese guy named Taguchi demonstrated that any deviation from Target produces a knock on cost (Taguchi loss function)
- this is the basis for methodologies such as 6 Sigma.
In manufacturing you will recognise the costs as (see list)

10. Too Much! Understanding Variation LSL USL _ X The key is to understand
- How much variation there is _ X

11. Understanding Variation
LSL
USL
Better..... _ X

12. Best? Understanding Variation LSL USL _ X
High degree of confidence unless something special happens _ X

13. Process Control May April March Feb Jan And how to control it
- Need to stabilise the process so that it is consistent.
March
Feb
Jan

14. Process Control
May
April
March
Feb
Jan

15. Inspection Product validation - Traditional Inspection What about….
Is the part good or bad ?
Is a concession needed ?
Is further work needed ?
Upper Limit
Lower Limit
What about….
Does the process need adjusting
Will the next part be good?
For SPC, one key element is required - DATA

16. Inspection to be used for continuous improvement
Data Approach
Quantify how good or bad process is.
Is ‘Tool A’ better than ‘Tool B’?
Is something wrong with the process?
Should I adjust the process?
How often is inspection needed?
Can tolerances be met?
SPC approach changes inspection from a NVA operation to a value adding continuous improvement tool.
“Confidence in the Process”
Inspection to be used for continuous improvement

17. Detection Prevention Summary Traditional Approach SPC Approach
Product
Inspection
Action on the product
Product Inspection
Rectification
Detection
Product
Information on the process
Action on the process
Man
Method
Machine
Material
Measurement
Environment
SPC Approach
Process control
Prevention
Traditional relies on inspecting to control quality – not really quality at all
SPC focus on measuring the process and product to control and assure quality
Key is to understand the important inputs to the process the relationship with the product and how to control them in order minimise variation, prevent rejects and assure quality.

18. Key Benefits
- Reduce waste due to Scrap & Repair
- Reduce NVA such as Inspection and unnecessary process steps
- Provide objective data for continuous improvement and new product development
- Create a LEAN environment by ensuring a stable and consistent process
Have confidence your process will achieve customer requirements – First Time & Every Time

19. Aerospace Aerospace invests large sums of money on metrology systems
CMM’s
Laser Trackers
Measurement arms
Machine probes
……..
Is the data being put to good use? Or

20. All Wrong Misconceptions “ SPC is only for automotive”
“ You can’t pull into the hard shoulder at 40,000 feet”
“ SPC is can’t be used for low volume production”
“ Aerospace tolerances are too tight for SPC”
“ CAA doesn’t allow SPC”
All Wrong
SPC is obviously used in automotive, but why?
- because the industry realised that quality need to be inherent in the process and SPC along with other advanced quality tools are absolutely necessary to achieve this. There is no such thing as cost of quality – the cost is non quality. The baseline should be 100% quality with any deviation adding cost not the other way around.
- 40,000 feet – refer to above. I would rather be in a plane where quality was inherent in the process rather than where it had been inspected in!!
- Low volume production – use different tools and focus on process & machine capability rather than traditional part number/feature based analysis.
- tight tolerances – result of caution and not understanding manufacturing capability – KC process
- CAA – who say’s? Aerospace quality standards EN9100 promote SPC (EN9103)

21. Aerospace SPC Some products are low volume......................but
There are lots of repeated features on a large component
Rib 2
Many parts are very similar and made using the same process
Rib 1
Rib 3
Rib 4
Focus on process and machine capability as well as product.
The solution is to carefully group characteristics, products & processes and use the correct SPC Tools.

22. Aerospace SPC But, long runs and high volume do exist!
Some elementary parts are produced in high quantities
Blades
Stringers
Ribs
Fastenings…
Lots of Key manufacturing processes are long run or continuous
Drilling
Bath treatments
Painting

23. Process Qualification
Aerospace SPC
- New Processes
- High Risk
Process Qualification
- New Machines
- Metrology systems
Equipment Selection
- Knowledge transfer
- Tolerance validation
- Statistical Tolerancing!
DFM
SPC Tools & Techniques
- Waste Reduction
- Cost Reduction
- Process Optimisation
Process Improvement
- Identification of critical process parameters
- Preventative/early warning control
Process Control

24. Fuselage Assembly Improvement Project Airbus France (St Nazaire)
Example Project
SPC Case Study
Fuselage Assembly Improvement Project
Airbus France (St Nazaire)
Presented by: Eric Leblais
Assembly Structures
SPC Integration Leader

25. Process Overview
Contact zone
Contact zone
joggling

26. Process Overview
Contact zone
Contact zone
Wedges are inserted between the Keel beam, front lower and rear lower fuselage sections.
Wedges
Wedges

27. Process Overview
BEFORE

28. Improvement Opportunity
Non-Value Adding process steps
Additional cost & assembly time

29. SPC Analysis
LSL
USL
Cp = 2.7
Cpk = 2.3
Proved Straightness and Joggling Process was Capable & Consistent.
Proved that Wedges & Shimming process were not needed.

30. Action Implemented Process Steps Removed AFTER Assembly time reduction
~ 10h !

31. Action Implemented Design Change Process Control AFTER
Lower fuselage of 15/21 section
Design Change
A new definition of the angles was required because of the removal of the joggling process.
Process Control
SPC Implemented for Lower fusalage section to monitor & control process

32. Results & Savings Money Gain 8 K€/MSN 8 MSN/month => 64 K€/month
Cancellation of the realization of joggling on the 8 angles.
Cancellation of wedges machining. (32 per Aircraft)
No more Gauging time. (~1h)
No more drilling and adjusting of the wedges. (~ 7h)
No more painting protection of wedges surfaces. (~1.5h)
No more fettling corrosion on the critical zones.
New feedback from the assembly to the design office.
Money Gain 8 K€/MSN
8 MSN/month => 64 K€/month
ROI = 3 MSN

33. Q&A Questions ? Ben Allister ben.allister@infodream.co.uk
Web:
Ben Allister
Questions ?