Maturity levels of masses

The maturity level of masses is a crucial aspect in the development process of aircraft and spacecraft, as it influences the accuracy and reliability of mass data. The masses can be available in different levels of maturity: estimated, calculated and weighed. Each of these maturity levels has its specific methods and sources used to determine the mass.

Estimated

If the mass is classified as "estimated", this means that it has been determined by scaling comparable products or based on the experience of the designer or weight engineer. This method is often used in the early stages of development when detailed data or physical prototypes are not yet available.

• Scaling of comparable products:This involves using masses of similar, already existing systems or components and adapting them to the new requirements.
• Experience of the designer/ weight engineer:The estimate is based on the expertise and experience of the engineers, who are able to make realistic mass estimates.

Sources for estimated masses can include historical data from previous projects, experience reports from suppliers or general norms and standards.

Calculated

A "calculated" mass is determined by mathematical calculations or computer-aided methods. This method offers greater accuracy than estimation and is used when more detailed information about the geometry and materials of the system or component is available.

• Simple calculation:The mass is determined by basic calculations such as volume times density. This method assumes that the geometric dimensions and material properties are known.
• CAD (Computer-Aided Design):Modern CAD systems make it possible to calculate the mass of a component or system based on detailed 3D models. These models contain information about geometry and materials that can be used for precise mass calculations.

Sources for calculated masses include CAD models, technical drawings and material data sheets provided by suppliers or internal departments such as quality control.

Weighed

The "weighed" mass is the most accurate method of mass determination as it is based on direct measurements. This method is used when physical prototypes or finished components are available.

• Scales:The mass is determined using a scale that offers a high degree of accuracy. This method provides the most reliable data as it is based on a direct measurement.

Sources for weighed masses include incoming goods, where delivered components are weighed, and quality control, which ensures that the masses meet specifications.

Evolution of maturity levels

The evolution of the different maturity levels of masses is crucial for the development process. In the early stages, estimated masses are used to make initial design decisions. As development progresses, these estimates are replaced by calculated and eventually weighed masses to continuously improve the accuracy and reliability of the mass data.

By using these different levels of maturity, engineers can ensure that mass specifications are always as accurate as possible and that the system meets performance targets.