Voicemail for Doors

Busy working on a new product: Voicemail for doors.  

If someone knocks on your door (or rings the doorbell), it prompts: "Hi, I can't come to the door right now. Tell me who you are and why you're here, and I'll open the door as soon as I can. <beep>"

Business Requirements

In the field of systems development, we distinguish between different kinds of requirements, such as top level requirements, business requirements, user requirements, and system requirements. 

Business requirements refer to the overarching needs and constraints imposed by an organisation's stakeholders on the solutions to a problem. They delineate the range of acceptable solutions to the problem, but without going too much into the solution. User requirements in contrast dictate needs relating to how the solution will be operated, maintained, and used.

Some of the business requirements, in order to be met, will also generate user and system requirements (eg business requirements to meet policies relating to disability).

Business requirements can derive from organisational policies, strategies, business case, and a range of other sources.

Examples of business requirements are:

• The solution must cost no more than $100m
• The technology platform must be AWS (or Azure, or Google) - for example, because organisational policy requires that IT solutions use these platforms.
• The solution must be fielded by 2nd quarter of 2025, to align with the strategy.
• The solution must meet data privacy policies.
• The solution must meet policies supporting users with disabilities.

Systems Engineering Bibliography

Buede, Dennis M. The Engineering Design of Systems: Models and Methods, 3rd Edition. John Wiley & Sons, 2016.

Strong focus on function analysis and decision analysis.  Good introduction to IDEF0.

Chapman, William L., Terry Bahill, and A. Wayne Wymore. Engineering Modeling and Design. Boca Raton, FL: CRC Press, Taylor & Francis Group, 2019.

Forsberg, Kevin, Hal Mooz, and Howard Cotterman. Visualizing Project Management: Models and Frameworks for Mastering Complex Systems. Hoboken, NJ: J. Wiley, 2005.

The rare project management book that gives emphasis on the critical importance of systems engineering.

Gibson, John E., William T. Scherer, William F. Gibson, and Michael C. Smith. How to Do Systems Analysis: Primer and Casebook. Hoboken, NJ: Wiley, 2017.

Teaches systems analysis (systems decision making) rather than systems engineering.  Systems analysis is an essential practice in systems engineering.  Bahill's book on trade-off analysis is another one of few books on the subject.

Hitchins, Derek K. Systems Engineering a 21st Century Systems Methodology. Chichester, West Sussex, England: John Wiley, 2007.

Kossiakoff, Alexander, Steven M. Biemer, Samuel J. Seymour, and David A. Flanigan. Systems Engineering: Principles and Practice. Hoboken, NJ: John Wiley & Sons, Inc., 2020.

James, Martin. N. System Engineering Guide Book. Springer, 1997.

Rechtin, Eberhardt. Systems Architecting: Creating and Building Complex Systems. Englewood Cliffs, N.J: Prentice Hall, 1991.

Sage, Andrew P., and Andrew P. Sage. Systems Engineering. New York: J. Wiley & Sons, 1992.

Stevens, Richard J. Systems Engineering: Coping with Complexity. London: Pearson/Prentice Hall, 1998.

Walden, David D., Garry J. Roedler, Kevin Forsberg, R. Douglas Hamelin, and Thomas M. Shortell. INCOSE Systems Engineering Handbook: a Guide for System Life Cycle Processes and Activities. Hoboken, NJ: Wiley, 2015.

Wymore, A. Wayne. Model-Based Systems Engineering: an Introduction to the Mathematical Theory of Discrete Systems and the Tricotyledon Theory of System Design. Boca Raton: CRC Press, 1993.