Updated: Mar 15, 2018
N.B. This information has been created based on personal experiences and research. It may be the case the others have varying opinions. If so please contribute to this blog by commenting below.
Computer-Aided Design (CAD) is the process of creating a digital mock-up to idealise, create, analyse and modify products within a virtual environment. It has many uses including mechanical design, electrical circuit simulation and hydraulic schematic creation. For the purposes of this blog, we are going to focus on the fundamental mechanical design and drafting packages. Ultimately CAD has the power to make or break a business due to the potential costs it can incur. These costs include obtaining the appropriate hardware to run the packages, licencing, maintenance, training, downtime (limited licences, system crashes or maintenance upgrades), work efficiency and input / output integration with other software packages or machinery. The important goal of implementing CAD into a business, like with many other engineering processes, is to get it right first time. However, with so many different packages at varying costs with different selling points, how can a business achieve this? To answer this question, we need to go back in time and look at how CAD has shaped the engineering industry, why it has branched off into many other industries and the positives / negatives of the main packages.
The whole philosophy of implementing automated techniques involves assessing whether a task can be completed quicker, easier and more accurately using computational technology as opposed to human output. The same philosophy began to occur with CAD in the 1970’s when computer systems had evolved enough to be able to perform the task of manual drafting. CAD software can be traced back to as early as 1957 when Dr. Patrick J. Hanratty developed PRONTO, the first commercial numerical-control programming system. In 1960, Ivan Sutherland MIT's Lincoln Laboratory created SKETCHPAD, which demonstrated the basic principles and feasibility of computer technical drawing. In the late 1960’s CAD software was further progressed to utilise 3D geometry in the creation of 2D technical drawings. This is an important point in the CAD history as it was when engineers were able to think and evaluate designs in a more natural manner, similar to the end product, before placing the final design on projected views with relevant dimensional outputs.
Over the next 2 decades CAD software continued to develop to a point at which most major engineering companies were investing in the software whether it be in buying it or developing it in-house. Many of today's largest CAD software development companies have originated from either major engineering companies who have developed the software in house, start-ups financed by major engineering companies or developed and then bought out by a major engineering company.
To better understand the most applicable software, it is important to understand what each piece of software is capable of creating. The main objective with CAD is to create a digital mock-up of a product with an input of various engineering and constraints, whilst it outputs critical dimensions either through a 3D file or on a 2D drafting drawing. With these inputs and outputs, we can now analyse suitable software packages. For examples, although widely used due to minimal cost and ease of use Microsoft Paint and Google Sketch-Up (yes, these are considered CAD software to many small companies or individuals with limited CAD training / understanding) are not viable engineering CAD tools. This is because these software packages are limited to single use and does not form an efficient process chain in product creation. This process is called Product Lifecycle Management (PLM) and forms the basis of CAD integration into the larger engineering network, from idealisation through to a finished product article. PLM could (and may well in the future) become a complete blog in its own right so for now we are only going to consider CAD integrating within the larger PLM network.
As stated previously, a variety of design and engineering inputs are required to create a CAD model. These inputs include designs (industrial, stylistic, customer based etc.), standards and regulations, physical boundaries (packaging envelopes) and many more depending on project requirements. CAD integration from these inputs is vital and can make a very big difference to the appropriate CAD software for your business. Similarly, with outputs the correct CAD software is dependent on what your business is trying to achieve. For example, we may be looking to 3D print a product (STL file output), laser cut a blank for a sheet metal component (DXF file output), physically machine a component based off of a 2D drafting or even output the geometry into a Finite Element Analysis (FEA) software. The list of outputs is endless and when you are assessing which CAD software to use, you must consider the PLM environment / process chain as a whole. Additionally, more advanced CAD software is capable of running many additional ‘modules’ within itself. An example of this is FEA tools or Computer Numeric Coding (CNC) tool paths built into the software.
Many comparisons between various software packages can be made with advantages and disadvantages to each but at the end of the day a senior official within the company will be tasked with signing off for the order of the CAD package. For this reason, it is vital that a business case is demonstrated and that the company will benefit financially from such an investment. This does not only include the cost of buying an initial licence or package but also maintenance, PLM integration costs, training and any additional requirements for the company to make change to for a successful implementation of the CAD package. Below is a list of CAD software which demonstrates a very rough estimation of such costs. As this list could be endless, we have stuck to the most common CAD packages for engineering applications. We say this as there are many other CAD packages which are very powerful but tend to be used in other industries. Examples of this include; Autodesk Revit (architecture and building) and Autodesk 3DS Max (gaming and photo realistic digitalisation).
Dassault Systemes Catia V5
Catia V5 is a widely used software for advanced mechanical design and large scale assemblies. When it was first released there was no other software capable of performing the tasks that it was. For this reason, it has maintained it's popularity with many large scale businesses and is often considered the most practical choice for businesses sitting in a supply chain network. It can be integrated with many PLM systems and has its own if no others are required. The drawback to its capabilities are the cost as Catia has very high licencing and maintenance costs. It is also run on a modular basis meaning the more application that are added to the system, the greater the licencing will cost. As it is considered a very advanced CAD software, it also requires a substantial amount of formal training. It's most common applications include design and engineering for aerospace and automotive due to its capabilities in solid modelling, surface modelling and assembly creation. It also has additional programming capabilities to create new tools to streamline the design process. However, due to the modular nature, it is likely Dassault Systemes has created the tools but they are often contained within another workbench.
Dassault Systemes Catia V6
Catia V6 is very similar to V5 in terms of cost and application. It has a refreshed interface and can be run on internet based software. The main difference, however, between V5 and V6 is that the PLM system is built entirely within the software. This makes it very difficult for companies with large scale projects to convert across to V6 as often a lot of critical information is contained within the previous PLM environment. For start up companies however, this is not a major issue unless you company sits within a larger supply chain.
Dassault Systemes Solidworks
Solidworks is widely considered as a scaled down version of Catia. It is much simpler to operate and is often the software of choice for teaching students about the basics to 3D CAD modelling. It has many built in applications the allow for analysis and simulation. A major drawback when looking at Solidworks for business applications is that it does not have an experience PLM system attached with it. This is not a major issue unless larger products / assemblies with many components and processes involved. As it is not as advanced as Catia in terms of capabilities of 3D modelling, it is significantly cheaper. It's main customers are educational institutions and smaller businesses performing the whole product lifecycle in-house.
Siemens NX (Formally Unigraphics)
Siemens NX is widely considered the direct competitor to Catia. It has many similar advanced functions and applications allowing the user to create many advanced mechanical products. As Siemens has a very advanced PLM system in Teamcenter, NX utilises this and makes for a very efficient concept to manufacturing process cycle. It also has a relatively updated and refreshed user interface and has good ease of use. It is however, quite complex and does require formal training. It's cost is quite high, similar to that of Catia however packages often come with Siemens own PLM systems and FEA packages. One of the major drawbacks of NX is that many engineering companies have been around since the inception of Catia and began to use Catia due to advanced nature compared to other CAD packages at the time. This makes it very difficult for a company to completely change over all their systems and processes as well as a very high cost of re-training users.
AutoCAD is the flagship software of AutoCAD. It's ease of use and low cost make it very attractive software for businesses who are manufacturing and have minimal 3D design work to perform. It has excellent capabilities in creating 2D drawings in particular site layouts. It has some 3D features but is not as comprehensive as most other CAD software. It also does not have an efficient PLM package contained within it often meaning additional processes are required to support the manufacturing phase. It is also very easy to learn and minimal formal training is required.
Inventor is Autodesk's more advanced engineering 3D modelling software. It sits in the higher end of the market but does not contain the advanced surfacing / shape creation features of Catia or NX. It is relativity high priced but is often bought as a package with other Autodesk products. It utilises Autodesk's own in-house PLM system however again, is not as comprehensive as pure PLM systems which are available. Its direct competitor is often considered to be Solidworks.
PTC Creo (Formally Pro Engineer)
PTC Creo also sits in the mid-range of CAD packages with its direct competitors being Solidworks and Inventor. It is quite a difficult software to learn and formal training is definitely required. PTC has its own PLM systems which integrate well with Creo. This also allows the software to be very powerful when looking at large scale manufacturing assemblies. It has quite substantial control of the design allowing it to be very parametric. Creo does not link well with other engineering software packages and is highly reliant on PTC's in-house products. It is often used alongside other CAD software due to its skills in working with advanced assemblies.
The above lists should have made it clearer and you should now be able to narrow down the choice of CAD software based on your business requirements. Looking towards the high end and higher cost, CAD products are able to easily integrate with other software but the packages are very complex and require quite a substantial amount of initial investment. In the medium spectrum, we begin to find the packages with smaller scale PLM software which can be integrated but it is more difficult than the advanced packages. The lowest cost products are very easy to use and require minimal training however they are very limited in their capabilities in terms of integration with other software or PLM packages. To further narrow down the products, I believe it is important to look at the end product of your business and really assess what you are trying to achieve. Complex systems such as aeroplanes and automobiles contain many different departments (electrical, structural, interior, large assemblies etc.) which need to be linked cross-functionally and definitely require the higher end CAD packages. In contrast, small companies that may only be producing singular parts can be mocked-up using the lower cost packages.
An important point to finish on is that CAD is just a visual representation of the end product. All that it is achieving is making it easier to interpret the specifications / design guidelines when manufacturing a product. This is important and should be analysed in terms of your businesses supply chain network. There is no point spending lots of many on software that is very difficult to integrate with your suppliers or customers.
The future of CAD is bright, there are many advancements being made in both PLM integration and parametric modelling. Many companies are now turning to reusability of the models with simple changes to the inputs and allowing the computer to autonomously rebuild the product with the new inputs. However, this should be met with a certain amount of caution as stress analysis may need to be performed on the new product to ensure it still fulfills its structural and safety requirements and innovation can end up being constrained. This is because the philosophy of parametric modelling is to reason by analogy and not return the product back to the fundamental requirements and assess if new technology has become available to make major medications to the design.
If you have any further points to add, please leave them below or send us an email. Additionally, if business support is required for setting up a new CAD software please don’t hesitate to contact Engineering First Principles and we will do our best to support your business. In a future blog, we hope to compare the various customers of each of the CAD packages discussed above. This should give an insight into which packages the industry experts consider the most viable to help with product creation of their chosen products. Stay tuned for more!
Thank you for taking the time to read this!