NASA defines workmanship as a shorthand term for the quality rules that apply to the assembly of electronic boards and electrical cable harnesses . It is also defined as the quality and accuracy of a pre-described or intended output that is constructed, usually, by a human with or without the use of aides such as machinery . High quality workmanship is not necessarily attributed to the talent of an individual but can be acquired through training, experience and control mechanisms.
Workmanship may be governed by quality assurance and production engineers, though, workmanship is also directly related to these other functions: Mission Assurance, Safety, Reliability, and Maintainability.
Workmanship is a critical area in all types and sizes of aerospace projects and missions. Also, it is of special interest for research groups that are involved in the aerospace field. Hardware and software for atmospheric and low earth orbit experiments are becoming easier to access, but this is not always accompanied with the proper workmanship training or techniques.
In the research of Dr. Swartwout , a common thread is discovered related to CubeSat failures. It was observed that in almost half of all failures:
- A configuration or interface failure between communications hardware (27%).
- The power subsystem (14%).
- The flight processor (6%).
More common examples of those failures:
- Batteries and/or solar panels not connected properly to the power bus.
- Insufficient power generation to operate the transmitter at a level needed to close the link;
- Unrecoverable processor errors.
All of the above can be classified as failures in functional integration, meaning that the spacecraft was not operated in a flight equivalent state before launch, and thus these easily caught mistakes were not discovered . Besides that, it is strongly believed that a large fraction of the “no contact” (45%) failures is due to poor functional integration, and thus as many as two-thirds of CubeSat mission failures are failures in functional integration.
The above results , shows that there is room for improvement in terms of Workmanship and Quality Control areas applied to CubeSat spacecraft development. Figure 1 shows the statistics for success/failure CubeSat missions from 2000 to 2012.
Figure 1: Mission Status by Launch Year . Swartwout, M. (2013): JoSS, Vol. 2, No. 2, pp. 213-233
Due to the potential hazards, cost of production and manufacturing, and overall technical challenges, NASA has created a separate committee to govern workmanship. It is termed the NASA Workmanship Technical Committee (NWTC).
The NASA Workmanship Technical Committee (NWTC) serves as the agency's technical authority to ensure that adequate workmanship standards and training for electronic hardware are available to NASA, its suppliers, and the aerospace community. In addition, The NWTC is responsible for documenting workmanship requirements and design criteria for the manufacture of space flight, aeronautics, and mission critical ground support electronic hardware .
In summary, the committee evaluates existing standards, creates new standards and/or best practice guidance, and training material to assist NASA programs, manage risk, and ensure safety and mission success.
- Most industry and especially NASA put great effort into properly training employees to produce consistent, high quality products and services.
- Proper training will greatly improve workmanship in most areas and the importance of it should not be overlooked.
Establishment of Workmanship Training can be conducted using the following four step approach:
- Training on all applicable procedures, standards, and best practices
- Instruct the student to make him/her become familiar with concepts and processes
- Provide hands-on practice
- Provide follow-up inspection of resulting product or service as a feedback mechanism
All training programs should include documentation that will provide results and or certification(s) upon successful completion of the course
Quality control mechanisms should be put in place to ensure adequate levels of workmanship. This can be accomplished through visual inspections or checks, tests, feedback loops from training, etc.
Proper documentation management and adherence to configuration management processes and procedures is also critical in maintaining a high level of workmanship. Documentation should include but not be limited to: non-conformance reports, incident reports, training material, processes, procedures and applicable standards.
Taking appropriate actions on training and quality control, a majority of workmanship related issues may be eliminated. As a point, remember that other production issues may arise such as:
- substandard materials
- non-adherence to proven process control
Let's review the fundamental Workmanship training steps:
According to NASA, all materials and configurations named in the Workmanship Standards are considered technologically standard and have demonstrated high reliability for a broad range of NASA missions and thus are mature .
The Workmanship Standards specify design, processing, and inspection requirements, which are relevant to the materials and configurations named, which ensure high quality hardware is supplied .
Suppliers are expected to perform manufacturing using controlled processes, which operators implement using established procedures, and which results in a product that is compliant with the Workmanship requirements .
Suppliers who use configurations and materials not named in the Workmanship Standards must establish that the resulting hardware will be reliable for the applicable mission and must establish, declare, and use relevant design, processing, and inspection requirements to assure that the final items have high quality .
Once more, the idea behind this module is to give a general overview of the workmanship training and the potential problems that can result from poorly qualified quality procedures. Specific safety recommendations and training in different areas (ESD, Wire Crimping and Harness, etc) are covered in separated modules.
We would like to invite you to see the next video from Dr. Don Carmont that explains the importance of pride in workmanship and its translation to other disciplines.