Detailed Design

Detailed engineering design

In general, detailed engineering design includes the following stages:

1. Checking specifications.
2. Defining subsystems, checking, and assembling parts.
3. Finalizing individual parts and accomplishing technical calculations.
4. Checking conformity with the standards.
5. Preparing and reviewing documents.

Detailed design iterations and final 3D CAD modelling of a product

As stated earlier, the engineering design is an iterative process where on each stage of a project you may need to return to any of the previous steps and revise project requirements, specifications or adopted solutions. Although the biggest chance of having a need for revision applies to the earlier phases of the product design, namely, conceptual and embodiment designs, during detailed design modifications are still possible.

Iterations of the detailed design should continue until the converging of the parameters and the relevant properties of the custom-designed parts and the off-the-shelf components.

Since in engineering design you can return from any design phase to any of the previous phases and make necessary revisions based on modified requirements and conditions, etc., such possibility is implemented in numerous 3D CAD modelling tools available to engineers and designers.

CAD modules relations

Selection of the off-the-shelf components and materials

Off-the-shelf (OTS) components (parts, products) are often called standard parts, and both terms can be used in the detailed design phase of the project development. Any mass-produced part belongs to this category and can be selected from production catalogues or assortments of goods: electric motors, bearings, screws and nuts, tires, video cameras, solar panels, conveyor rollers, etc.

Therefore, the first choice in any detailed design should be given to the standard parts if they meet the project requirements. Beside the reliability it can also significantly reduce production cost of the new product.

• Compatibility of OTS components with the designed product

Compatibility of a component with the designed system can be considered from various viewpoints: overall dimension or mass, type of the used power or technology, permissible load, feasibility, acceptable or legitimate type of application, and so on. Most of these criteria are considered and evaluated in the phases of conceptual and embodiment designs.

• Material selection and its influence on design

The main goal of material selection is to minimize cost while meeting product performance goals. Usually, the key parameters during the material selection are strength, rigidity, reliability, and durability of the part. Also cost and availability are essential. Altogether, these factors characterize the best material for a specific product as the one that provides the best value, defined as the ratio between overall performance and total cost.

• Ordering standard parts and materials

Important notes for selection of suppliers:

1. If you are considering a possibility to purchase materials or OTS components from a foreign supplier, not only the cost of the product and its delivery should be considered. Sometimes custom duties must be added to the expenses, and they may be non-negligible.
2. While planning project milestones and building a Gantt Chart, you should not forget delivery time for purchases. Standard delivery time to Canadian customers from local suppliers is 2-3 days, from US – up to 10 days, from Europe – about one month, and from Japan – 2-3 months. These numbers are approximate, exact delivery time from different suppliers can be vary.