Editor's Choice

The devil is in the detail – the importance of design engineering

March 2022 Editor's Choice

All man-made physical objects started out as a brainwave, or a defined user requirement, or an idea converted into a design, whether it be a building, a cabinet, a machine, a motor vehicle or a space shuttle. Historically, these designs started with various iterations on paper until approved for construction.

In modern days, most designs start out in the virtual world before being committed to paper and in some cases get transferred digitally from the design ‘package’ into the manufacturing machine without ever touching paper in the physical world. The additive manufacturing sector is a great example of this.

For most people the design process may be seen as trivial and not as exciting as the final product, but if neglected it can have far-reaching, often fatal and even catastrophic consequences:

• In the 1990s, four fatal airplane accidents were caused by design defects.

• Eleven children under the age of 12 died in 2012 due to design defects in toys.

• Approximately 265 000 injuries stemming from design defects were treated in American emergency rooms in 2012.

• A design defect made by GM in 2001 involving ignition switches caused at least 31 car crashes.

• When 56 major incidents in Europe were analysed in the 1990s, 59% of the causes were attributed to the specification and design process.

It is thus critical for any individual or company involved in engineering and design to ensure adequate governance and control so as to protect their clients, the end user and themselves. Detailed design and engineering follows a process which entails conceptual design, model design and detail design (from front-end planning all the way to general technical specification) and when executed in a professional manner, eventually results in a well-designed solution or product for the required application.

In the conceptual design phase, drawings are the main deliverable. The drawings may initially only consist of simple ideas with a minimum amount of detailed information. The main objective of the conceptual phase is to capture the discussed ideas in a written format. This process is typically iterative until the best option has been selected and agreed.

The model phase of the design and engineering process uses the concept agreed on previously and develops it into a workable system. To get to a workable solution, it needs to be modelled and remodelled iteratively until the solution conforms to the parameters and control regulations as agreed with the client (while also keeping in mind company, country and international legal, health, safety and environmental standards and regulations). During this phase, engineers will typically follow a framework of clarity, simplicity and safety in achieving the design goal. Part of this process often includes HAZOP (hazard and operability) studies to ensure product or solution safety. The output from the model phase can include more detailed drawings, simulations and models.

The detailed design phase is where the design is refined, resulting in plans, specifications, detailed models (2D, 3D or physical), piping and instrumentation diagrams (P&IDs) and bills of quantity (BOQ) amongst others. This phase may also include the development of full cost estimates as well as procurement schedules.

So why is detailed design and engineering so important?

Years of study and implementation within the project’s environment (civil, mechanical, electrical, instrumentation, automation, industrial, structural) have proven numerous times that the detailed design and engineering process is a critical phase in a project where the cost is correctly defined and set.

It is also at this phase of the project where the most (inevitable) unexpected costs can be reduced, if not eliminated. It is thus critical that this phase is managed and controlled, as it is instrumental for cost control and can result in major financial impact on the project if neglected. In addition, if done poorly it can also have a major negative impact on the overall project success and customer satisfaction.

Very often companies will do the concept design and go straight to procurement with it as a requirement. This typically results in one of three outcomes:

1. The prices provided by respondents are widely disparate and mostly overpriced, as risk is built in by experienced vendors who know what the risks are. This makes adjudication very difficult and the clarification process cumbersome and lengthy. This also o ften results in the tender/RFQ being cancelled and re-issued a few times until prices are more comparable. This is frustrating for all parties and can delay any project by months, if not years.

2. A contract is placed but there are huge cost and time over-runs as the scope is not clearly defined or misunderstood and the BOQ is incomplete or non-existent. This results in unexpected costs as a result of missing components or missed functions, costing additional money. Some projects get put on hold or cancelled due to budget constraints. Sometimes the contractor’s contract gets cancelled due to non-delivery and high cost. Once again, a frustrating outcome for all parties concerned.

3. A contract is placed and the project is completed with acceptable time and budget over-runs, but the solution is incomplete although usable. Not all project objectives are met and there is a lot of rework after delivery over an extended period of time, eating into operational expenses and resulting in a mistrust of the solution. The result is frustration for all concerned.

How to ensure that detailed design and engineering is successful

The main objective of the detailed design phase is to ensure that the overall design solution satisfies the project’s objective whilst also complying with industry, legal and regulatory requirements. To achieve this, the inputs and synergy of various specialists are required to assure that the most effective solution (in terms of time and cost) is produced.

To ensure success, a person or entity will need to take control of the various stakeholders and manage them. Often a project manager will be appointed to bring all the interested parties together to work towards the common goal, resulting in a full, detailed design and engineering solution.

There are many frameworks that engineers will adopt in reaching the detailed design phase of a project. In essence, each of them takes the idea or concept that solves a problem from an initial idea/concept design to one that is detailed and solves the problem.

The skill of detailed design is to balance out-of-the-box thinking, best-in-class solutions, fit-for-purpose solutions, proven legacy solutions and regulatory requirements and refine this during the process until the solution fits the project’s financial, technical and commercial requirements. This is better left to the professionals.

For more information contact Gerhard Greeff, Iritron, +27 82 654 0290, gerhard.greeff@iritron.co.za, www.iritron.co.za


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