4.1 industrial design overview & dfx.pdf

Industrial Product Design

Prof. H.M. Thakur, Prof. M.H. Kulkarni, KIT's COEK

Product Evolution


Over the years, what has improved? Product Variety

Performance Features

Superior Ergonomics

Product Durability

Raw Materials

Aesthetics

Without Industrial Designers, contributing in shape, size, human factors, ergonomics; Maruti would have probably prepared just another car and not the masterpieces it offers today.


Critical Goals of Industrial Design Utility Products human interface should be safe,

easy to use and instinctive. Each feature should communicate its use to its customers.

Appearance Form, line, proportion and colour are used to integrate the product into a pleasant whole.

Ease of Maintenance Design must communicate easy maintenance and repairs.

Low Costs Form and features have an effect on cost of the product.

Communication Design should communicate its Design Philosophy and Mission through visual qualities.


Design for X (DFX Methodologies)

Customer needs and specifications are useful to drive conceptualization part.

After this, when preparing the design for production, there are many difficulties in linking the concept features to manufacturing constraints.

For this, many methodologies are used, known as Design for X or simply DFX Technologies.


Design for X (DFX Methodologies)

Design for Manufacturing

Design for Production

Design for Assembly

Design for Recycling/Disposal

Design for Life Cycle

Design for Environment

Design for Efficiency

Design for Robustness

Design for Serviceability


Design for Manufacturing

It is the most popular DFX Methodology. It addresses manufacturing costs of the product,

thus it is a universal methodology. Product cost most important factor towards

economic success of the product. Product success depends on the profit margin and

how many units of the product sold by the company.

No. of units sold depend many times on overall product quality.

Hence, DFM basically deals with enhancing Product Quality while minimizing Product Costs.


Needs for DFM

Sketches, drawings, product specifications, and design alternatives.

A detailed understanding of production and assembly processes.

Estimates of manufacturing costs, production volumes and ramp-up timing


DFM ProcessEstimate the Manufacturing Costs

Reduce Assembly Costs Reduce Overhead CostsReduce Component Costs

Consider effect of DFM on other factors

Re-compute Costs

Good Enough?

Acceptable Product

Y

N


Estimating the Mfg. Cost


What are different Mfg. Costs?

Mfg. Costs

Components

Standard Custom

Raw Material Processing Tooling

Assembly

LabourEquipment & Tooling

Overhead

SupportIndirect

Allocation


What are different Mfg. Costs?


Bill of Materials (BOM)Item No.

Part Name Req'd per Assy

Name of Material

Form Spec Qty Purch Unit Cost ($$)

Vendor Code

Total Cost

1 Assembly-Lock 1

2 Key 2 Steel SAE 1020 Strip 1/8"x1" 3 $1.20 RSC $3.60

3 End-Shackle 1 Steel CRS Bar 1/4" th 3 $1.80 RSC $5.40

4 Front Shackle 1 Steel 3035K Bar 1/2" rd 2 $10.00 RSC $20.00

5 Keyway Assembly

2

6 Keyway 1 Teflon 1301 Sheet 1/2" sq 3 $32.75 UFI $98.25

7 Assembly Shackle

1 Steel 3035K Bar 1/2" rd 3 $10.00 RSC $30.00

8 Spring Shackle 4 MIL-S-11316 Plate 8 $0.10 KDS $0.80

9 Assembly Back

10 Spring Back 2 MIL-S-11310 6 $0.08 KDS $0.48

11 Post Back 1 Steel 3035k Bar 1/2" rd 3 $10.00 RSC $30.00

12 Back 1 Steel SAE 1020 Strip 1/8"x2" 3 $2.04 RSC $6.12


Estimating Cost of Standard Components

Comparison to a similar component currently being purchased by you. Estimate weights, materials, reliability requirements, other features like aesthetics, usability.

Asking suppliers and vendors selling such parts for quotations. Provide them with complete technical drawing and details of the part, functionalities expected, material required, etc.


Estimating Cost of Custom Components Prepare all technical drawings, specifications like materials (all the

materials with their specifications), methods (Processes needed for manufacture), men (resources needed for manufacturing) & machines (tooling required for manufacture).

Calculate costs for each part in all three aspects raw material cost, process cost, labour cost & tooling cost.

Allocate proper material wastage allowances (5-50% for casting, 25-100% for sheet metal parts).

Allocate allowances for processes like break down time, setup time, loading and unloading time, material movement time, etc.

Allocate allowances for labour like time spent waiting for earlier process to finish, time for wearing protective equipment, fatigue allowance, etc.

Allocate allowances for tooling like tool breakage, tool sharpening, etc.

Add them together.Prof. H.M. Thakur, Prof. M.H. Kulkarni, KIT's COEK

Estimating Cost for Assembly

As number of sub-parts go on increasing, cost for assembly goes on increasing.

If the quantity of manufacture is not significant, assembly is mostly done manually.

Assembly cost estimation involves work study. Study the assembly process for a large quantity and take average. Take records for allowances i.e. Time wasted, time in loading unloading, etc.

Multiply by average labour rate. Consider increase in wages for some time ahead.


Estimating Overhead Costs

All costs which do not lead to manufacturing of products are overhead costs.

Difficult to estimate because of variety of products and variety of resources. Determining how much weightage of overheads to be given for each product is very difficult.

The future cost of supporting a product line is even more difficult. (Training, Recruitment, etc.)

Most firms use Overhead Rates or Burden Rates applied to cost drivers like Raw Material cost, Labour cost, etc.

Problem with this is that it assumes overhead rates to be directly proportional to cost drivers. This is always not so. Increase in RM price need not affect cost of transport, cost of inspection, etc.

Activity Based Costing (ABC approach) Increase the number of cost drivers and assign overhead costs in proper proportion. E.g. Product Complexity increases cost of inspection.


Cost Augmented BOM

Sr. No. ComponentPurchased Material

Processing Cost

Assembly CostTotal Variable

CostM/c Tooling Cost (Non-recurring)

M/c Tooling Lifetime

Expectancy (Units)

Unit M/c Tooling Cost

Total Cost

1 Comp. 1 1,457.00 230.00 1,687.00 1,07,34,567.00 5,00,000 21.47 1,708.47

2 Comp. 2 365.00 56.00 421.00 13,87,203.00 2,50,000 5.55 426.55

3 Comp. 3 107.00 38.00 145.00 8,76,504.00 2,50,000 3.51 148.51

4 Comp. 4 45.00 10.00 55.00 2,56,743.00 3,00,000 0.86 55.86

5 Comp. 5 90.00 13.00 4.00 107.00 13,24,545.00 3,00,000 4.42 111.42

6 Comp. 6 23.00 3.00 26.00 26.00

7 Comp. 7 41.00 5.00 46.00 46.00

8 Comp. 8 57.00 4.00 61.00 61.00

9 Comp. 9 10.00 5.00 15.00 15.00

10 Comp. 10 5.00 3.00 8.00 8.00

11 Comp. 11 3.00 1.00 4.00 4.00

12 Comp. 12 6.00 2.00 8.00 8.00

Total Direct Cost

2,209.00 347.00 27.00 2,583.00 1,45,79,562.00 35.79 2,618.79

Total Overhead Cost

104.00 233.00 11.00 10.00 358.00

Grand Total 2976.79Prof. H.M. Thakur, Prof. M.H. Kulkarni, KIT's COEK

Components Cost Reduction

Understand the process constraints and cost drivers impractical tolerances, unnecessary processes can turn into cost drivers. E.g. Internal corner radius needing specialised machinery.


Component Cost Reduction

Redesign components to minimize processing steps. Combine different parts together, eliminate separate assembly and finishing operations.


Component Cost Reduction

Black Box Approach For components that are procured purchased directly.

Tell your suppliers what you want, not how you want it. Provide specifications, dimensional constraints, performance requirements, etc. But do not tell them your concepts.

It is possible, that a supplier specialising in that part might come up with a better design than yours.


Assembly Cost Reduction

Design for Assembly can act as a subset of DFM here.

Assembly costs are a small fraction of the total cost of the product.

Focusing on assembly cost gives you part count reduction, reduction in product complexity, reduction in support costs.



Keeping Score along with ongoing estimates of cost of assembly, an efficiency of assembly operations is measured as a factor.

Theoretical Minimum No. Of Parts x (3 seconds)

DFA Index = ------------------------------------------------------------------------

Estimated Total Assembly Time

3 seconds is a theoretical minimum time period to handle and install a part that is perfectly suitable for assembly.



Integrate Parts wherever possible, combine two parts together in construction itself so that minimum assembly operation is required.

It does however, increase the complexity of the product, increase the production time as fabrication of two combined parts is added.



Ease of assembly some methods

Part is inserted from the top of assembly

Part is self aligning

Part does not need to be oriented

Part requires only one hand for assembly

Part requires no tools

Part is assembled in single linear motion

Part is secured immediately upon insertion



Consider Customer Assembly Customer will be willing to take care of some of the assembly tasks, if it leads to ease of handling, ease of transport, etc.

Although, the product has to be designed such that, even the inept of the customers, who might even ignore instructions must be able to assemble the product.


Overhead Cost Reduction

Reduction in component and assembly costs helps overhead costs in many ways.

Part count reduction means that there are less components to store, so inventory management is minimum.

Reduction in assembly means less workers for inspection, which in itself is a non value adding operation.

Reduction in complexity means that there is less engineering support needed.


Overhead Cost Reduction

Error Proofing error proofed product designs ensure that the operations are carried out in the way desired by the company to a high extent. This reduces a lot of defective products and cost spent in their rework, recycle, etc. is avoided.


Consider impact of DFM on other factors

Impact on development time

Introducing a product early in the market has its benefits. (Remember Xerox)

Suppose a part manufactured with DFM saves you Rs. 1 Cr, but it takes 6 months to develop, then it will not be worth halting the entire production line for 6 months.

Particularly about products in a dynamic market.



Impact on Development Costs

DFM certainly affects time spent in development and money spent on it. But, it is observed that, this effect is very small.

Also, conscious and honest efforts in DFM are beneficial in the long run.

With practice, experienced design teams can minimize time and money spent on DFM.



Impact on Product Quality

Remember, purpose of DFM is to minimize cost while not affecting the quality adversely.

It is possible that in the excitement of costs being saved, we may be tempted to compromise about quality. Teams must make sure they are careful here.

Optimisation is the key..


Consider impact of DFM on other factors Impact on External Factors Study in DFM may even be beneficial to other

products of the company, so efforts on DFM may be combined for many products to save costs, time and efforts.

Life Cycle Costs The costs for disposing of toxic or harmful substances in products while recycling must be considered beforehand as a societal need.Service aspects like Guarantees and warrantees are not considered in mfg costs but these factors needs to be considered while DFM.


Results of DFM

Today, DFM is essential part of all Product Development efforts.

It is usually an activity going on throughout product life cycle. It is never too late to save money.

Remember the benefits of better, yet cheaper products like modern day computers.

Pl. Read Page 222 to Page 233 carefully.


Welcome to the court of Emperor

Jalaluddin Muhammad Akbar


Noble men! There is a very important

matter before the court today.

The raw material price is shooting up. The material cost of a

sword has gone up by Rs.10 . And . We are adding 50,000 soldiers to our army this year.

I want to handle this situation

without increasing the

taxes. Please give your valuable

suggestions as to how we should

face this situation.


!?

!!??

Why everyones quiet?

Birbal! I am surprised that you too have become silent!!


!?

!!

??

Your Majesty, I have six ideas which can reduce the cost of a

sword by atleast Rs.20 without

compromising thefunctional

requirements.


!?

!!

??

Brilliant!.Tell us those

ideas.


Presently, the hilt has 7

parts. The proposed design will

have 4 .

Existing Design

7 parts

New Idea

4 parts

Part Count Reduction


For the new hilt,instead of designing

exclusive rivets, we can use the rivets of

daggers.

Part Commonisation

xProf. H.M. Thakur, Prof. M.H. Kulkarni, KIT's COEK

When the Shah of Persia was our Guest

last month ,I observed that the hilt in his sword does not

have a curved portion. We can design similar

hilts for our experienced soldiers.

Benchmarking

New IdeaExisting Design

Curved portion


Alternate Material

Blade

Sheath

Copper Steel

The sheath which houses the blade

is made of copper now.

We can switch over to Alloy steel which is

cheaper.


Weight Reduction

Blade

Sheath

Since alloy steel is stronger than copper,

we can reduce the thickness by 0.5 mm

which will save material

2 mm 1.5 mm


Yield ImprovementThe curved blade

design is yielding only 2 pieces per die. If a straight

blade is designed, we can extract 3pieces per die.

2 Blades 3 Blades


Your majesty. The present design is being used since the time of

Baburwithout any failure.

We should not risk any design change.


Saheb, there is no doubt that the present sword designed by you

for my Grandfathers army is superior.

However, let us testthis new design in our barracks.If they pass

the tests, we will deploy them in the

battle field.


If the ideas pass the test, we can save

atleast Rs. Ten Lakhs this year, thus

serving the purposeof cost reduction.


There is an advantage also. I

do not have to increase the tax.


Birbal! I wonder how you developed

these ideas! Is there a systematic

way by which others can also be

trained to generate such ideas.


Yes, your Majesty. With the help of Functional

Analysis System Technique(FAST)any body can generate such

ideas. FAST is a powerful tool used in Value Engineering (VE) which is an extremely effective

system to improve products and services for cost and productivity

improvement.


If six ideas for the sword itself can

save Rs. Ten lakhs , imagine how much

money we can save on other weapons like spears, arrows and

cannons etc.


Birbal! There are four divisions in my army Infantry, Cavalry,Artillery and Elephant

brigade. I want you to teach the engineers in each of these divisions the application of Value Engineering (VE), especially the

Functional Analysis System Technique(FAST). Each division should

release Armoury Change Requests (ACRs) for the worth of Rs.25 lakh.


Yes, your Majesty.


4.1 industrial design overview & dfx.pdf

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