Software's: How do they affect Design for Manufacturability? Which CAD to buy?

Computer Aided Design (CAD) Systems have allowed us to become more creative in the way we work, but their ever evolving capabilities, power and time required to learn using them ultimately affects Design for Manufacturability. One must always remember that CAD Systems are just tools, nothing more.  

Here’s a good case study and a true story, to support this blog A company specialized in cabinetry design and manufacturing decided to put in place a top notch Engineering department, and to support it, they purchased a high-end Computer Aided Design (CAD) System with a high-end Product Lifecycle Management (PLM) System. The problem was not the applications themselves, but rather this company purchased the system without having a thorough understanding of the requirements associated to a Product Development Process (PDP). To make matters worse, there was no PDP in place at the time of the purchase.  This resulted in months (up to two years) of customization of the applications, while trying to fill customer orders, which in the end were very late, required numerous reworks, generated a significant financial loss and a no confidence vote in the systems put in place.  

Misunderstanding CAD Systems

It is not uncommon to see companies buying the wrong CAD System. This usually happens because we get blinded by the technology and some non-technical people truly think that it is the CAD System that designs the product. Ever heard the expression “Computer Designed” as a sale pitch? The CAD System is just a tool, and like any other tool, you need to know what you want to do with it before buying it. 

Consideration in the selection

Companies should develop their own considerations based on their PDP and products that ultimately leads to the selection of a CAD System. One cannot arbitrarily select a CAD System without answering (at least) the very basic questions listed hereafter and incorporate the answers in the requirements that will ultimately narrow the selection to one system. The perfect CAD System is the one that meets your requirements based on your PDP. Before putting a penny in a CAD System here are some points you should consider: 

• Purpose: What do you want to accomplish?
• Application: Aircraft, Marine, Space, Bridge, Building, Furniture, Electronics etc… Don’t try to shoot a bird with a canon,
• Ease of use—Productivity: Think of the people that will be using it,
• Training: How long is the training and how long to become proficient?
• Functionality: Consider what you need first, and then look into the nice to have. Consider the evolution of your business as well,
• Software Evolution: Some applications versions are not compatible with one another,
• Vendor stability: Make sure the selected vendor has a sound financial base, and a good track record,
• Support: Is it included, and how will future version affect your operation? Will you always need external support? Think $$$!
• Cost: it should be the last thing in your mind. Think of the Return on Investment (ROI) instead. Besides, accountants will always find the price too high, even if it’s a free open source CAD. Choosing the right CAD System that will increase productivity and reduce the design lifecycle is the only cost consideration that matters,
• Expert opinion: Ask for support from an independent CAD Expert not associated to any CAD supplier,
• Compatibility: think of compatibility with your production floor, especially if they work directly from 3D models,
• Suppliers and Customers: Do you need to be compatible with your suppliers or customers. E.g.: Aircraft OEM generally require full compatibility with their system,
• Manufacturing Functionalities: Does your CAD need to be integrated with the shop floor?
• Libraries: Is the CAD system compatible with commercial of the shelf standard parts libraries (bolts, nuts, screws…),
• Collaboration: Do you need collaboration functionality? It is useful when multiple designers work on the same assembly. This will tell you if you need a PLM application.

Your CAD Community

One of the building blocks of DFM is collaboration between functions. This is why you should involve all functions directly involved in the development of your product (except finance) to be part of the selection team. These functions should also have some level of proficiency in the use of the selected CAD System. Since they will be using a common tool, this will allow for a better collaboration among functions. 

The Ripple Effect

There is no stronger support for a CAD System then trust that it’s the right one, and trust in the PDP. This will lead to an efficient working environment where people will question how they can improve the system, rather than questioning the validity of the CAD system itself. Having the wrong CAD system in place will generate frustrations amongst functions and having no PDP in place to support the CAD will lead to people or functions working individually around the problem, therefore leading to a multitude of problems that will undoubtedly lead to a corporate wide disaster.

Closing Comment

Purchasing a CAD system requires knowing how one needs to work via a robust PDP and then list all the considerations supporting the PDP to purchase the right CAD System. There are professional consultants who are not associated to any CAD suppliers offering services that should be considered. Remember that once a CAD System is bought and put in place, only to find out you got the wrong one, will create a deep gouge on your bottom line.

Part Proliferation, Why it takes away your competitive edge? Part 4: Raw Materials

Last blog we looked at fasteners and how their proliferation affects your bottom line. In this blog we will look at Raw Materials. They have a direct impact on design, supply, and manufacturing total cost when standardized. If not standardized, it can drive up the total cost of your product.

An Aerospace company kept buying aluminum extrusions that had a minimum buy condition attached to them, and never seemed to deplete the stocks because every Engineer/Designer unknowingly specified different extrusions. However very close in dimensions, the extrusions were still different, therefore were ordered under different part numbers.   

If unchecked, raw materials can easily clutter a material storeroom. This clutter is created by the Engineers’ and Designers’ lack of visibility on what is in stock. Typically the choice of material will stop at what meets the immediate design need without regards to what is in stock, which in most case could do the job just as well.

Influence of Raw Materials,

Raw materials come in all shapes or forms that will later be transformed into components then be part of a product. Regardless of the industry, Raw Material can easily account for about 30% of the total cost of a component. Obviously, having our Aerospace Company as a scenario; inventory cost will be added over the already existing 30%.

Raw Materials are mainly classified by Format and Chemical Composition (or alloy in the case of metals, or essence for wood). Every variation of Format and Composition will generate a different material, therefore a different material stock number. Using our Aerospace Company as example; although the extrusions were aluminum alloy and shapes were the same, the extrusions shapes were of different dimensions, most of the time small differences. If the Engineers/Designers would have been aware of what was in stock, they could have designed their components around one single extrusion, thus avoiding the thousands of dollars in inventory. 

Considerations in selecting Materials

From what was discussed above, it is very obvious that one should select a raw material that is stock in the factory. However if what’s in stock doesn’t work, before selecting a material, consider the following:

• Number of parts that will be fabricated: Part volume can drive the selection of material format, as well as the transformation process.
• Availability of the material: Exotic materials are expensive and create delivery problems and are likely to have a minimum buy clause attached. Common raw materials are generally available and delivered within 24 hrs.
• Make from: Can existing parts be used as raw material and modified to suit the need? This will save time in design and minimize inventory.
• Corrosion: What are the environmental conditions? Are you dealing with dissimilar materials that can generate galvanic corrosion?
• Stress:  Vibration, creep, fatigue, strength, cracking, etc...
• Toxicity: Some materials generate toxic fumes when processed, e.g. beryllium copper.
• Dimensional Stability: Dimensions can be affected by temperature change, humidity levels, etc.: e.g. wood expands under humidity, Stainless steel warps when welded, etc...
• Transformation Process: Machinability, weldability, Formability, e.g.: Some aluminum alloy cannot be welded; Stainless Steel has poor Machinability, etc...
• Surface Protective Finish: Can it be avoided? Some metals do not require protection. Stainless steel can replace a painted carbon steel part, and will save the costs associated with painting parts.
• Environmental: Chemical transformation processes are harmful to the environment. Think green when you select a material or when specifying a Chemical process.

Raw Material initiatives

Raw material selection is done at the Design Process level, therefore should be defined as early as possible, and should be kept as much as possible to what is stock or easily available. Designers are solely responsible for material selection, and indirectly define the manufacturing process by design. This is the main reason why manufacturing and Material Management need to be involved early in the design process in order to design manufacturing and material management into the product. This exercise will also help defining a preferred raw material list.

The Ripple Effect

Having a preferred material list will have ripple effect on engineering activities, as well as purchasing and manufacturing. Having engineering use company standard raw materials minimize design uncertainty of using a new material which very often require testing and certification. It will minimize material shortage and having to buy materials with a clause of minimum buy. It will also maximize savings since the same material can be purchased at a higher volume. Manufacturing will be more stable since the mechanical behavior of the company standard material used are known and controlled. At the end of the day, it will help minimize the design and manufacturing life cycle.

Closing Comment

Raw materials are often taken for granted and the selection is done by Engineering with little regards to the production process that follow. This is not done maliciously, but  it is the result of a lack of visibility very often not given to Engineering as the everlasting motto is still being used; Engineering defines the WHAT, and Production defines the HOW.  Engineering and production function should define the materials concurrently so availability and manufacturing process stability is designed into the product.

Part Proliferation, Why it takes away your competitive edge? Part 3: Fasteners

Last Blog we looked at ways to cleanup parts off the inventory as well as the ripple effect this cleanup may have on your bottom line. In this Blog we will look at fasteners. They can have an immediate impact on design, supply, and manufacturing total cost when standardized.

Influence of Fastener,

Fasteners have been around for centuries; in all shapes or forms and materials, for all kind of applications. Typically, the application is what drive the selection of a type of fastener, the environment is what drives the material selection. There are however other factors that will influence the selection of a fastener: The tooling available on the factory floor and method used (robots, auto-feed screwdrivers, manual installation etc.) to install the fastener will also have a predominant influence on the selection, and these factors are often forgotten, only to be figured out during critical design reviews when 90% of the manufacturing cost has been committed by design.  Although fasteners are typically the smallest and the least expensive components in an assembly, if they are not properly selected and standardized, they can prohibitively drive up the cost of assembly, therefore compromising the competitivity of the product on the market.

Consideration in selecting fasteners,

Companies should develop their own considerations based on their manufacturing process and products that ultimately leads to the selection of a fastener or group of fasteners for a given application. One cannot arbitrarily select a fastening system without answering (at least) the very basic questions listed hereafter and incorporate the answers in the design. Selecting the fastening system for a given product early in the design process will lead to a conscious decision that will have an impact on the committed cost of manufacturing:

Application: Aircraft, Marine, Space, Bridge, Building, Furniture, Electronics etc...

• Load Case: Tension, Shear, Fatigue…
• Limitations: Structural, Non-Structural, Fatigue, Creep, Secondary Stress...
• Environment: Corrosive, Liquid, Space, Temperature, Salty...
• Type of joint: Fastened, Bonded, Permanent, Structural, Non-Structural...
• Joint Material: Metal, Plastics, Rubber, Concrete, Wood, Composites, Dissimilar materials...
• Number of fastening components: Screw or bolt only, washer needed, nut needed, Inserts, nut plates, self tapping...
• Installation methods: Manual, Mechanical, Quick Turn, Robotics...
• Tooling: Auto-feed, manual, robot, jigs, special tools, power tools, Access...
• Access: From top, from bottom...
• Security/Safety: Lock-wire, lock features, vibration, loosening, fatigue...
• Fastener hole Type: drilled, tapped, self-tapping…
• Fit: Clearance, loose, Press-fit...
• Head Design: Flat, Hex, Fillister, etc….
• Drive: Slotted, Hex, Philips, Robertson, Hex Socket...
• Size: Diameter and length...
• Availability: Stock, COTS, Custom...
• Fastener initiatives

Initiatives in fastener standardization will have a significant impact on total cost. Obviously the least expensive fastening system is no fastener at all, but this is another subject. The easiest way to limit fastener types is to impose a limitation on designers and educate them on what is preferred from a manufacturing point of view; the Designers are the ones selecting the fasteners. One easy way to do this, is by creating boards showing the preferred and accepted fasteners, but with today’s CAD systems, coupled with Fastener managing Systems such as SynchroFit – Vistagy and Cenit AG,  the preferred fasteners and what is common stock can be modeled and kept in a library that is linked to the Master BOM, giving full visibility to designers of what is available at all time.  In fact, Designers should always design with what is available on the factory floor. Any new fastener introduced to the factory floor should be thoroughly analyzed as the impact on factory activities can be significant.

The Ripple Effect

Minimizing the types of fastener in inventory will maximize the buying power, therefore lower cost via an economy of scale. The effort and cost to create a library and database will pay for itself in time saved in engineering, but mostly in time saved on the factory floor.  Further initiatives should thrive at designing for the least number of fastener type, and even to design for no fasteners when possible.

Closing Comment

It is a known fact that fastener types have proliferated in product development, to the point where the true selection criteria's are becoming blurred.  Understanding the influence of fasteners and how we select them will lead to significant savings on the total cost of product development. It is worth putting the effort to create initiatives that will lead to a more judicious use and a better selection of fasteners, while reducing cost.

Part Proliferation, Why it takes away your competitive edge? Part 2.

Last blog we looked at what causes part proliferation and why it takes the competitive edge out of companies. In this blog we will look at solutions that can potentially help manufacturers to reduce their inventory of parts sitting in the warehouse.

Standardization of parts,

The best way to avoid proliferation is through standardization of parts. For a company that has a legacy of parts a thorough analysis of all parts must be performed to create groups and families of parts to clean up the system. Parts that are the same must be consolidated into one part number. Parts that are similar in shapes and function can be consolidated into one part which can then be modified as required. Creating a Standard Bill of Material (BOM) of preferred parts and making it easy to consult using Off-the-Shelf applications will control and avoid the proliferation of parts. Unfortunately an iron fist is required to maintain a cleaned BOM, and this doesn’t mean that the system has to be inflexible, but rather the opposite. The flexibility is created through the designing of parts that can be modified for multiple purposes when required or the simple reuse of engineering or designing around Off-The-Shelf parts. It all starts at the very beginning in the definition phase of products.

The Zero-Based Approach,

In the previous blog we referred to this approach as the Empty Drawer or Empty Room concept. Dr. David M. Anderson has developed a similar method to reduce and cleanup parts off an inventory. The Zero-Based Approach is based on the principle of: “What is the minimum list of parts type we need to design new products”. This approach literally starts at zero and adds only the parts that are truly needed from an overwhelming list. It is like emptying a drawer and just put in what we want, rather than taking out what we don’t want. The latter takes more time as wanted and unwanted items are cluttered together. The exercise of cleanup your BOM using the Zero-Based approach must be done with a vision of developing products with a minimum of parts that can be reused in different designs.  Obviously once this is done, a decision has to be made as to what will be done with the unwanted parts. Again, don’t send then back to the store room.

Designing for Standardization,

Standardization must be designed into the product. Designing for standardization, other than engineering a product, is in fact a consolidation of activities aimed at defining, evaluating availability, purchasing, and sustaining supply of parts during the concept phase in the development of a product. Before any lines are drawn on a CAD, the use of preferred parts, reusing already designed and tested parts or designing new parts is defined in a concurrent manner involving at a minimum; Engineering, Supply Chain Management and Manufacturing. This trio must reach a consensus on parts; their supply and how they will reach the production floor on time, without inventory, and zero Work-In-Process (WIP).

The compounded effect of working in a One-Piece-Flow environment and Standardization will virtually eliminate inventory and completely eliminate WIP, therefore resulting in substantial financial savings, and product out to the customers faster.  

The Ripple Effect,

Standardization has a ripple effect on the operation of a company that develops products. The financial savings will come in the forms of: No inventory to support, less parts means less  effort to purchase, better purchasing leverage due to a higher volume of the same parts ordered, reduced floor space means no need to expand to have more room, less overhead cost, better quality due to a lesser number of different parts to support. Having the product to the customer faster also means better financial returns and repeat business. It also means that supplier will have savings as well as they will supply a higher volume of the same parts, therefore passing savings onto the customers to repeat business, yet still be profitable.

Closing Comment,

Companies that have adopted standardization as a mean to control their part proliferation have seen their inventory, and WIP virtually eliminated and Total Cost reduced, making them more profitable and competitive than they were before, and allowed them to develop new products better and faster. Standardization is not something that is technically complex, but will require leadership and vision. Cleanup the system using a zero-based-approach is a fast and simple method to create a BOM of preferred parts. Professionals like Dr. David M. Anderson have proven that standardizing parts, the total cost of developing and producing products is dramatically reduced, and the exercise typically pays itself within 3 financial quarters.