Requirements Analysis

Requirements Analysis is one of the Systems Engineering tools to do the design and optimization of a system.

A system as a whole has a statement of what we want it to do. This is in the form of goals, values, mission description, performance requirements and such. It also needs ways to measure how good a given design is. These can be things like "minimum cost", "minimum waste output", and "maximum efficiency". These statements and measures are often in verbal form. Requirements Analysis is the process of putting them in numerical form, breaking them down to more detail, and assigning them to functions who will perform them. The assignment ensures that somewhere in the system the top level goals are met. At the most detailed level a subset of the requirements are assigned to a single function box. This now becomes the conditions that a specific engineering design needs to meet.

Some stability is needed in requirements so that the design work can proceed. How to document the results of this analysis task and when to change it needs to be determined.

Global Village System Identification

The first step is to identify what is the system we are working with, and what is outside the system (the environment). The Global Village Construction Set is a set of machines and technologies, but are not sufficient in themselves. You also need land on which to use the machines, people to operate them, and information so the people know what to do. These combine to form a Global Village System (GVS), which as a whole serves the purposes for which it is designed.

The environment in which the system operates is everything outside the boundary of the system, in other words the entire rest of the universe minus the system. Among the outside entities the system can interact with are more copies of itself. You can define inputs and outputs that flow across the system boundary. As a time series, at first more inputs are required, otherwise the system would be empty. During it's operating life both inputs and outputs will occur. If the system reaches an end of life and is dismantled, then outputs will outweigh inputs until nothing is left, and all parts are disposed of properly.

Multiple versions of the system can exist during design as alternatives. Once design is completed, multiple versions can exist to account for differences in number of people, land area, climate, geology, starting funds, diet preference, and surrounding region economic state and technical infrastructure. As a starting point, a single nominal "design point" can be established, from which versions can be derived.

Source Statements and Measures

This is a list of source statements and measures for what the Global Village System is supposed to do, and then a restatement in a measurable form.

From OSE Mission:

• "remove material scarcity" > Provide a surplus of free time and useful outputs from the system after accounting for internal needs and inputs from the environment.

• "harmonious coexistence between natural and human ecosystems" > The system maintains and improves itself with a minimum of non-renewable inputs and waste outputs.

• "land stewardship, resilience, and improvement of the human condition" > This is met by the above two statements.

• "everybody's needs are met" > Provide sufficient surplus against times when a person cannot contribute due to age, health, or other reasons and to account for mechanical failure or natural variations.

• "replicable...communities" > Maximize the ability of the system to copy itself, as opposed to building from scratch as the first copy has to be, and allow communities to grow in number by seeding or fission (in the biological sense).

From OSE Specifications:

Top Level Requirements

• Provide a surplus of at least 1.2 times labor input, in other words (total output/total input) > 2.2 times input.

Rationale: The ratio of total people to employed persons in the United States is 2.2, and thus each employed person supports 1.2 additional people. The GVS should be at least as productive as that. Employed persons and GVS labor input both do not account for non-job activities such as household chores.

• Operations and maintenance of the system less than 100% of system capacity.

Rationale: In order to maintain and improve itself, the GVS as a whole needs to spend less than all it's outputs on itself. For example, if you spent 100% of your labor time growing food, you have no time left to do anything else. Similarly other components need to used less than 100% to have some capacity left over for improvement and growth.

• Minimize non-renewable inputs to less than 100% relative to conventional equivalents.

Rationale: The Earth has a finite supply of non-renewable resources. Thus for long-term sustainability use of those resources should be minimized. The GVS should use as little as possible, but at least below the average of the surrounding community who are not using the GVS. If the GVS can produce an equivalent surplus output, for example biodiesel for sale, then use of petroleum-based inputs no longer falls into the "non-renewable" category, and use can then be negative (outputs exceed inputs).

• Minimize waste outputs to less than 100% relative to conventional equivalents.

Rationale: Similar to the previous rationale, the Earth has a finite ability to absorb waste outputs which degrade the environment. Therefore the GVS should produce as little as possible, but at least below that of the surrounding community. If you can take in a local waste product, for example paper that would otherwise be burned or go to a landfill, and use it to make something useful, like papercrete blocks, that would count as negative waste, since you are reducing total waste in the environment.

• Maximize the percentage of system components that can be efficiently produced by the system.

Rationale: A certain amount of outside inputs are required to set up the first copy of a GVS in a given area. By producing it's own parts, additional copies will require less inputs. Copies can be made from seeding or fission. Seeding is by a GVS providing a minimal "starter set" to set up another GVS, which then grows to a full version. Fission (or mitosis biologically) is by a GVS growing to twice it's original size, then splitting into two complete copies. The "efficiently produced" means relative to getting it from an outside source. For example you may need a computer to control automated fabricators. CPU and memory chips, and hard drives are produced in highly specialized, expensive factories. So they cannot (at present) be efficiently produced locally. Structural metals, however, can be fabricated with relatively simple equipment. The useful measure then may be the ratio of (amount of that component produced/equipment needed to produce it).