Approaches to Design Development Flashcards
What is sequential engineering?
Traditional engineering, also known as sequential engineering, is the process of marketing, engineering design, manufacturing, testing and production where each stage of the development process is carried out separately, and the next stage cannot start until the previous stage is finished.
What is concurrent engineering?
Concurrent engineering, also known as simultaneous engineering, is a method of designing and developing products, in which the different stages run simultaneously, rather than consecutively. It decreases product development time and also the time to market, leading to improved productivity and reduced costs.
What are the benefits of concurrent engineering?
Rationalisation:
The CE approach ensures that design will be rationalised for the capabilities of the manufacturing system, which is going to convert the design to reality - a physical part that can be produced through a physical process. The team focuses on a common goal instead of conflicting departmental goals.
• Working in parallel:
The primary CE advantage is that many processes occur
concurrently rather than sequentially - things are done
simultaneously rather than in a linear fashion. For example, manufacturing engineers can begin to evaluate tooling while the design is still being finalised. Similarly, the documentation process can start virtually on the same day as conceptual design.
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• Reduction of lost time caused by communication
breakdowns:
Since the multifunctional teams have the same objectives, they strive to be more open and available to input from each other. Communications tend to be more frequent and less formalised. In a linear process the team is divided. A lot of time is spent on needless conflicts.
• Pre-empting errors and spotting problems early:
With concurrent engineering, there is a much greater chance of pre-empting errors and spotting problems while they are still easy to fix. When products are finally released for production there are fewer changes, while the ones that do crop up are usually relatively minor.
• Flexibility to accommodate changes:
When work is done in parallel, it provides the team with flexibility to accommodate changes and the ability to adapt quickly to changed situations or requirements. This ability to accommodate changes at any
stage in the product cycle (beginning, middle, or end) provides a smooth flow of information among the involved organisations.
• Providing the best overall input:
The benefits of concurrent engineering reach far beyond the usual collaboration between engineering and manufacturing. CE brings concentrated resources to bear on the task. For instance, various individual disciplines also benefit from working in parallel on product development. In a growing variety and complexity of the products that we manufacture today, close cooperation between mechanical and electronic design is critical to speedy development. Co-operation is fruitful to other disciplines as well - industrial design, conceptual design,
structural analysis, technical documentation, etc. When teams and disciplines cooperate with each other, the mutual outcome is likely to be better and faster.
• Decreased occurrence of obsolescence:
The large interval between system development and
deployment during traditional product design increases the possibility of obsolescence before the product is ready to be marketed. In CE, since time-to-market is reduced, the effect of obsolescence on the life-cycle cost is greatly minimised. As a result, CE not only saves development cost due to shrinking time and schedules, but it also reduces non-recurring costs (such as parts qualifications, tooling, inventory, stocks, manuals, support equipment, etc.) that would have incurred otherwise.
• Cross-training:
A multifunctional group can help each other get up to speed quickly. Cross-training reduces the learning curve.
• Better use of scarce technical resources:
If the product development cycle can be shortened, then project personnel can be made available for the next project sooner, thus improving the company’s use of scarce technical resources.
• Other Benefits:
In addition, several of the firms that have adopted the practice of concurrent engineering reported reduced lead time for creating bid proposals: shorter
product development times (in design phases); reduced product development costs; parts reduction; lower inventories, fewer rework orders, smaller scrap piles, improved quality, and reduction in production costs
[McKnight and Jackson, 1989] (during fabrication, manufacturing and
What can be the disadvantages of concurrent engineering?
• Risk of wasted effort:
With the CE approach, there is a greater degree of risk of human resources doing something in parallel that is not required and thus creating intellectual inventory, which may clutter up the working environment. Intellectual inventory is also created in serial design processes. However, with CE, where the goal is to cut the product development lead time, the consequences could be far more taxing.
• Possible increase in iterative costs:
In certain circumstances, CE can probably increase some of the design costs because it is an iterative process and some portions of the work will have to be redone. For instance, one may have to repeat the process when better ways are found to configure the product or when manufacturing discovers a need for change in product design to enhance manufacturability. There is a slight possibility that with CE one can go overboard in iterations, especially during early phases, thereby taking more time than necessary. But its impact on reducing the total time can still be justified.
• Concurrent chaos:
One of the benefits of CE is that incomplete or uncertain information can be used at an early stage. This means some processes, which were initially accomplished sequentially, can now be performed in parallel. However,
sharing immature or imperfect information early may result in increasing the number of life-cycle areas affected. If such affected areas are not controlled, it can lead to what is normally described as “concurrent chaos”.
• Errors can build up:
There is a concern that engineers can go overboard and engage in more simultaneity than necessary. As more and more key activities, which lie on the critical path, are done in parallel, there may be no slack time left. This increases the risks of committing errors. It may take teams’ valuable time away from key activities to correct errors, leading to the possibilities that corners will be cut. As a result, the overall quality of the end-product may
suffer.
