From False Starts to Precision Landing: The Evolution of Requirements Management

Requirements management originated in U.S. rocket programs between 1945 and 1970. A small management trick contributed to the success of the Apollo program.

Where do we come from?

In 2023, Jean Pierre Berchez and I presented the idea history of Scrum at REConf conference. At the end, we asked the audience if the requirements managers were aware of their own history.

Since no one could answer our question, we investigated the origins of requirements management and presented our findings the following year. We wanted to know how requirements management came about and how this technique spread to Europe.

Our research is based primarily on the work of Stephen B. Johnson. He has researched and published extensively on the US missile program. 

The origins of requirements management can be traced back to the systems management of missile projects in the United States. To build rockets that could successfully take off and deliver their payload, several disciplines had to work together effectively, including military representatives, scientists, engineers, and managers. For instance, the first moon landing required the collaboration of approximately 300,000 individuals from 20,000 suppliers and 200 universities spanning 80 countries. It quickly became clear that interfaces were particularly important for everything to work. Despite organizational changes and technological advancements, requirements management remained a constant.

Rocket theory was researched at the beginning of the 20th century

At the beginning of the 20th century, three pioneers developed a theory about rockets simultaneously and independently. These pioneers were Konstantin Tsiolkovsky (1857–1935), Robert Goddard (1882–1945), and Hermann Oberth (1894–1989). The Nazi German military financed large-scale rocket development. This resulted in the Aggregat 4, also known as the V-2 rocket. Figure 1 illustrates how these pioneers influenced each other.

Fig. 1: Network of early rocket pioneers

Following World War II, Wernher von Braun (1912–1977), Walter Dornberger (1895–1980), and Kurt Debus (1908–1983) moved to the United States as part of Operation Paperclip, along with others. There, they continued developing the V2 rocket. Successor models played an important role in the American space program. Von Braun and Debus were appointed directors at NASA.

The United States developed intercontinental ballistic missiles during the Cold War

In 1954, Bernard Schriever (1910–2005) began vigorously pursuing the development of intercontinental ballistic missiles (ICBMs) as deterrent weapons. The Air Force commissioned the development of the Atlas and Titan missiles. At the same time, the Thor missile was being developed as a medium-range weapon. The development of the missiles was uncertain and marked by failures.

The Atlas and Titan were liquid-fuel missiles, meaning they had to be refueled before launch. This process was cumbersome, dangerous, and time-consuming. These missiles were not suitable for a rapid military response. In 1956, scientists began developing solid rocket fuel. This new propulsion system meant the weapons could be deployed immediately. This required the development of new missiles. In this case, they were Minuteman missiles. From a military point of view, solid-fuel rockets are more interesting. (The Atlas, Titan, and Thor rockets that had already been produced were later used as launch vehicles for satellites and spacecraft in space programs.)

Sam Phillips established configuration management at NASA

Samuel Phillips (1921-1990), the project manager for the Air Force, discovered Boeing's configuration management during the development of the Minuteman missile. He immediately recognized its benefits for missile development. Many failed launches were due to components from different manufacturers not fitting together. Changes to individual components were necessary. However, it was important that everyone involved be aware of the changes. Phillips resorted to a trick: he linked configuration changes to the obligation to provide information on their impact on time and cost schedules. This enabled him to complete the Minuteman program on time and under budget.

At an Air Force management conference in 1962, Boeing presented the process in more detail. /1/  Configuration management consists of three functions:

• Identification Control: Means for defining and identifying precisely every element of the evolving system from initial requirement through the delivery of operable systems, including all supporting data, drawings, and hardware.
• Change Control: Means for controlling the effect of changes and for implementing them in the most expeditious manner.
• Accountability Control: Means for recording identification and changes associated with the evolving system configuration, including supporting data, drawings, and hardware.

Further details are mentioned in the article:

• A formal system must be in place to record all technical requirements and “end items” of a system.
• A naming scheme is needed for all end items.
• A configuration manager reports to the program manager. Each line department also has employees responsible for configuration management.
• The configuration manager heads a change board comprised of representatives from various departments, enabling all involved parties to approve necessary changes.

Later, Bernard Schriever loaned Samuel Phillips to the Apollo program. Together with Acting Director George Mueller (1918–2015), Phillips streamlined the loose management structures at NASA's research centers and established configuration management. /2/

Fig. 2: Network of rocket/missile development in the US

Those interested in more details should take a look at the book “The Secret of Apollo: Systems Management in American and European Space Programs” by Stephen B. Johnson. /3/

Requirements management arrives in Europe at the end of the 1960s

Around the same time as the Apollo program, several European countries and Australia joined forces to develop a rocket system. The European Launcher Development Organization (ELDO) was tasked with creating a European launch vehicle. ELDO was doomed to fail from the beginning. First, there was no common goal backed by political support. Second, ELDO lacked the management expertise to successfully launch the rocket. Of the planned 11 launches, only nine took place. Of these, only four were successful. The participating countries withdrew. ELDO was dissolved in 1973. The relevant facilities were then incorporated into the European Space Agency (ESA).

Around this time, several researchers founded the European Space Research Organization (ESRO). ESRO modeled its organization after CERN. ESRO developed research satellites and collaborated closely with NASA because it depended on their launch vehicles.

NASA supported ESRO and its participating companies in establishing the necessary management structures. For instance, ESRO awarded Junkers the contract to build the HEOS satellite. Junkers received assistance from Lockheed. The two companies wrote the bid together in Sunnyvale, California. Particular emphasis was placed on managing such projects.

Another example is the development of the ESRO II satellite. In this case, the British company Hawker-Siddeley received the contract. This company received considerable support from TRW. TRW was founded by Ramo and Wooldridge.

NASA offered to launch the first two satellites into space free of charge. Experts from the Goddard Space Center provided ESRO staff with intensive support.

Boeing invested in the Bölkow Company for space projects. Consequently, there was a lively exchange between American and European managers.

NASA successfully launched the ESRO-I, ESRO-II, and HEOS satellites into space in 1968. Cooperation with the Americans intensified further in 1973 with the construction of the Spacelab. ERNO, a German company that sought McDonnell Douglas as a systems engineering partner, worked on the Spacelab.

Configuration management originated at Boeing. In missile programs, the idea arose to maintain configurations with the same level of care as models, hardware, software, and documentation. This concept evolved today into the development of the digital twin.

This article originally appeared on May 8, 2024, in a shorter form under the title “Wie entstand das Anforderungsmanagement?” on the HOOD company blog.

References

• /1/ Wood, Lysle A.: Configuration management. In: paper delivered at the Air Force Systems Command Management Conference, Monterey, Calif. 1962. S. 2-4. available at Google Books: https://www.google.de/books/edition/_/fKTI_yqt0BMC
• /2/ Johnson, Stephen B.: Samuel Phillips and the taming of Apollo. Technology and culture, 2001, 42. Jg., Nr. 4, S. 685-709. abrufbar unter https://www.jstor.org/stable/25147800 (free registration required)
• /3/ Johnson, Stephen B.: The Secret of Apollo : Systems Management in American and European Space Programs. London: JHU Press, 2006. https://www.press.jhu.edu/books/title/2845/secret-apollo