5.2 - Personal Production: Functional Analysis

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Analysis ApproachEdit

The next step in the Personal Production example is to divide the project into more manageable pieces that can be individually designed. Since the equipment will grow and evolve from a starter set, there is a strong time element. So our first division is into a sequence of project phases that meet increasing levels of the total goals and requirements. Part of the growth will be how many people are in the community the project serves, so the phases also scale in quantity of outputs. This keeps the equipment from being over-sized for the number of people involved. Operation on a smaller scale in the early phases should also provide some feedback for later design improvements. The equipment is also intended to directly support some of the needs and desires of the owner-operators. So where outputs like food, shelter, and utility services go, and how they are used, is an integral part of the project. We will include these items as part of our complete system analysis.

With limited people to work at the conceptual design stage, we cannot examine every possible alternative at present. Therefore we will make one set of functional flow diagrams as a starting point, and leave variations for future work. We also plan to follow the reference architecture laid out in section 3.4. Given more time and people, later design work can go back and look at improvements and variations.

Project PhasesEdit

Figure 5.2-1 - Personal Production expansion phases.

Figure 5.2-1 illustrates an example division of the project into expansion phases, starting with a conventional workshop, and six phases numbered 1A through 1F (you can click drawings for larger versions). Six is an arbitrary number of divisions of what is really a continuous expansion. We chose it as a reasonable compromise between number of phases to analyze and complexity of the additions in each step. The diagram is a partial functional flow type illustrating the time sequence, but it only shows some of the inputs and outputs. Conventional shop equipment and new parts and materials are inputs from outside the project.

The process starts with building a conventional workshop in the lowest box. We use construction tools and inputs of lumber, sheet metal, etc. and use those to assemble a building, then install the remainder of the workshop equipment. The completed conventional workshop is an output from the first function box. Along with additional outside parts and materials, we use the conventional shop tools to build the first Phase 1A expansion elements. These will be a set of added equipment that can process more materials, make new kinds of parts, etc. The loop marked "Phase 1A Expansion Elements" indicates as soon as a new piece of equipment is finished, it starts being used to help build more equipment. When the full set of Phase 1A elements are finished, we transition to the next function and start building Phase 1B. As equipment accumulates, we must also expand the building(s), roads, outdoor space for solar collectors, etc.

We continue building expansion phases in sequence through the final Phase 1F. During expansion, our ability to make our own parts and materials grows, but our target is ~25% at the end of the expansion. Therefore all the phases still require new parts and materials from outside that we cannot make ourselves. The final box, "Operate Phase 1F Location" indicates the factory is complete according to this design, and outputs the full range of products for the community, plus whatever replacement parts are needed for maintenance. This diagram does not show the outputs of final products, but all the expansion phases will do so, in increasing amounts over time.

Because we have not done more detailed analysis yet, we will assume geometrical growth in community size in each phase. The minimum size is assumed to be a community of 25 people, with eight owner-operators. This allows one person per starter set machine, and an assortment of skills for early construction and assembly. The first group of people build a conventional workshop, then start to build the starter set for Phase 1A. The end of each build phase from 1A to 1F assumes a factor of ~2.175 growth in the community, to 55, 120, 250, 550, 1200, and 2640 people. The percentage of needs & desires met is assumed to increase linearly by 4% per phase starting at 1% for the conventional workshop, so 5, 9, 13, 17, 21, and 25%. These assumptions require increasing scale and diversity of equipment and skills for each phase.

The owner-operators are not expected to design their own equipment. Rather they are provided with designs and instructions, and in some cases actual hardware, from a previous research and development phase. The R&D can operate in parallel with the project phases. It would deliver product designs as needed, rather than all up front.

Top Level FunctionsEdit

To the outside world, the entire project can be treated as a single function box with inputs and outputs (see Figure 4.1-1). From within the design process, the edges of that function box are treated as the System Boundary, the logical division between the system we are designing and everything outside that we are not (see Figure 4.1-2). The inputs and outputs across that boundary can then be broken down into separate flows by type: Energy, Food, Water, Parts and Materials, etc. The question then becomes how to break up the sub-tasks internal to the boundary into smaller pieces. We choose as our approach the reference architecture described earlier in the book. The first level of division is by general type of activity: making things (Production), using things (Habitation) and moving things (Transport).

This is not the only way you can divide up the project, but we think it is logical way to apply the rule of Functional Relatedness. This rule organizes functions that are more related to each other than to other functions into one group at the next higher level of a project. One reason for doing that is it places sequences of related tasks and the flows between them in a more compact and understandable layout. Another is optimizing groups of related functions is easier than trying to optimize everything at once. Changes to the related functions have less effect on the rest of the project, so they can be updated independently.

Lower Tier FunctionsEdit

There is not sufficient information in the top three function boxes to identify what external flows link up with them, and what the flows are between them. To find that out, we begin a process of breaking down each function into smaller parts, identifying their inputs and outputs, and repeating until we reach individual items that are simple enough to design. Rather than creating this breakdown from scratch for each of our four example designs, we adopt the one from the reference architecture in section 3.4 as our starting point. Box and arrow type functional flow diagrams help understand how the parts of a system are connected, but they don't have room for full descriptions or technical data. We link the additional information to the diagrams by using the same names and numbers within the diagrams as reference labels on the other data.

Since the factory will grow in phases by additions to the previous phase, we don't need to create a completely new set of diagrams each time. Instead, our higher level diagrams will be based on the completed project (Phase 1F). We will eventually make a version of the lower tier diagrams for each phase, showing what items were present in the previous phase, and what is added or changed in the current one. Therefore they represent slices in the time dimension of the project, with each slice showing the physical relationships at that time.

1. Provide Production CapacityEdit

Production is numbered first among our three top level functions, because logically it comes before using the products for living space or transportation. In practice, though, the all three top functions will operate mostly in parallel. Figure 4.1-3 shows the bare breakdown into second-tier functions. The core of the production flow is the sequence from extracting raw materials such as ores, processing them into finished materials such as metal alloys, fabricating parts from those finished materials, and then assembling them into finished products. To these core steps, we add a control function to issue commands to the production equipment, supply power to operate them, and store inventory as needed between steps. Lastly we have growing organics as a separate item because living things perform self-production in a fundamentally different way than human designed equipment.

Again, there are other ways the Production function could be divided up, but we think this is a logical way of grouping related tasks. The numbering sequence is also arbitrary, but more or less in time order so that flow arrows will proceed from left to right. In this form the diagram is incomplete. Next, we need to describe each function in more detail and what the flows are that connect them. This defines the scope of the tasks that a given function includes. Rather then repeat the generic descriptions from the reference architecture in Section 3.4, please refer to those, and we will note differences and added details here.

1.1 Control Location - This function provides overall control of the Personal Production sites and systems, including production, habitation, and transport. It takes as input the designs for the locations, and for end products, which are provided from the previous R&D phase. The degree of automation in the control systems starts out low for the conventional workshop, and will increase by phase.

1.2 Supply Power - This function is to supply all forms of power for the project, and converting it as needed to other forms. A significant surplus is an end goal. We expect to use conventional utility power at first, adding solar furnaces for direct heating and thermal storage, and photovoltaic, wind turbine, and bioenergy systems later to increase renewable sources and reduce outside dependence.

1.3 Extract Materials - This includes local supply of raw materials, using Personal Production equipment. The project goal is to obtain a significant share of total materials from new local supply, internal recycling, or from outside waste sources. As the space required grows beyond home garage/basement scale, project members may need to build new sites sites. Therefore conventional heavy equipment or self-building such equipment is an early priority.

1.4 Process Materials - This includes conversion of raw materials to finished materials inventory, ready for storage, parts making, or consumption. It can use chemical, mechanical, thermal, electrical, or other processes, and operate as a continuous flow or in separate batches. Early outputs may include concrete, basic metal shapes, glass, and wood for basic construction, with other products added later.

1.5 Fabricate Parts - This takes as input finished materials from processing or storage, plus outside materials supply. These are transformed into finished parts ready for assembly. Early processes for this function can include casting metal, glass, and concrete shapes, and machining wood and metal parts. Additional machines and processes would be added during expansion phases.

1.6 Store Inventory - This task includes storage for materials, parts, and completed items not currently in use. It includes storage for other Production functions, and long term storage for Habitation and Transport. Because of similarity, we also group environment protection and control (i.e. buildings) for the other production functions, and land for industrial tasks under this heading.

1.7 Assemble Elements - This includes combining parts and materials into higher level assemblies (collections of parts), leading to completed elements. It also includes dis-assembly of elements for maintenance or modification. Assembly includes movable elements like production machines and vehicles, and construction of fixed elements such as buildings. At first, most of the parts for assembly will come from outside sources, with the percentage decreasing through the phases.

1.8 Grow Organics - This includes growing microorganisms, plants, and animals to the point of harvest. Pets and ornamental plants not included in this category. They are placed under Personal Items in Habitation. Growing organics includes the land space to grow biological products, including within Habitation areas. This land includes owned, leased, and harvest rights. Early land may be undeveloped, and used for extraction before upgrading to other purposes.

2. Provide Habitation CapacityEdit

The Personal Production project as a whole is intended to satisfy some of the needs and desires of the owner/operators and the local community. This includes necessities like food, shelter, and utilities, and some optional items for hobbies and entertainment. The Production functions provide the physical items and primary services. The Habitation functions supply the locations where they are used. Habitation includes all types human-occupied space outside of production and transport. Production and transport may include habitation elements. For example, a factory building may include restrooms for the people working there, and a passenger vehicle may include heating and cooling. They are included by necessity, but they are not the primary purpose of those elements. Conversely, a kitchen is a materials processing area, and may share equipment types like furnaces (oven) and mixers with the production area materials processing. But the end purpose of a kitchen is to provide food and drink to people, not to make other kinds of products, so it is put under the Habitation heading.

Habitation includes residential, commercial, and public use space. Buildings share common parts, like foundations and roofs, regardless of their use, and some buildings can be mixed-use. Therefore our functional breakdown is by type of human needs being met rather than by use of the building. The natural environment is often uncomfortable and sometimes hostile to humans, so we create shelter to modify the environment to our liking. Functionally we divide this into passive elements that protect us, and active elements that control and modify the local environment. Once we have safe and comfortable surroundings, we next provide for the internal needs of the human body in the form of food and drink, and maintaining health. Basic items like shelter and food are necessary for everyone to live, but beyond that the majority of most people's time and occupied space is taken up by other activities which are more optional and diverse. We divide supporting these activities into the physical, which are personal items like furniture and clothing, and information, which is not tied to a specific physical item. Once we define these various functions in more detail, their required inputs and outputs then become demands which the production function needs to meet.

Personal Production has a goal of supplying up to 25% of what people need and want by the end of Phase 1F. So the majority of the next tier functions listed below are supplied by conventional means, like paid jobs, savings, and retirement income. Later in the design process we will determine which products and services are easiest to provide and give the most return for the effort put into them.

2.1 Protect from External Environment - This includes passive protection of people and other habitation elements from weather, water, insects, and other outside factors. It also includes structural support of all habitation elements, the underlying land for it to rest on, and outdoor protective clothing.

2.2 Control Internal Environment - This function covers actively managing the internal environment created by the protective shell in terms of temperature, humidity, lighting and other factors. It includes controls and sensors, the active hardware which produces the environmental changes, lighting, windows, window coverings, and emergency systems.

2.3 Provide Food and Drink - This includes supply of food and drink materials at the point of use, local storage, food preparation, serving, dining, and disposal of food and drink wastes.

2.4 Maintain Health - People are included as an essential element of the project. This function is assigned the actual people and their inputs and outputs, as the most relevant place. It also includes sleep, sanitation, exercise, cleaning of persons, cleaning the internal environment, filtering, health monitoring, first aid, emergency services, and examination and treatment.

2.5 Provide Personal Items - This includes the internal volume of private living and storage space, public/community space, and commercial space. It also includes the physical contents of all these spaces and decorative/non-protective clothing.

2.6 Provide Information - This includes communications, storage, and processing in all forms, for personal, commercial, teaching, entertainment, or general information. It does not include operational information for production, although they may share hardware and software elements.

3. Provide Transport CapacityEdit

Transport is the third top-level function. It is required because sources of supply, locations for production, and final points of use can all be different. Only part of the community's needs and wants are being supplied by project production, so we need to import the remainder from outside sources. We also need to deliver some items for sale, move items internally at a site, and community members need to travel from place to place, for work or by choice. All the movements may use similar types of transport elements, so we organize their lower tier functions by type of item transported rather than where it is going. Transport elements can be mobile or fixed (like roads), and they can be owned by the project or by other entities. Project-owned elements can be custom designs, while non-owned elements generally are not. One shared design, like a utility truck, may serve different cargo types. The functional division of tasks allows analyzing the needs for each, then considering specialized or shared equipment to satisfy them.

Like Production and Habitation, only part of the community's total Transport needs are met internally by project elements, with the remainder provided by conventional methods. The functions below represent the total needs. Later design work will determine which parts will be met by the project.

3.1 Transport Bulk Cargo - This includes bulk solids, both incoming and outgoing, or being delivered between project sites. It includes items for sale, or to use internally for expansion and maintenance. Bulk items don't need special packaging or protection during transport.

3.2 Transport Discrete Cargo - This includes individual items that need protection from the environment, shocks, and vibration during transport. They may need special packaging to protect items from each other. Discrete cargo is typically smaller, so multiple items may be delivered in a single shipment.

3.3 Transport Humans - This includes the transport of humans between project sites, and to and from outside destinations. It also includes internal transport within a site, but the scale of sites in this example mostly will not require it. Humans have many of the same needs as discrete cargo, plus a desire for higher safety levels and comfort, schedule priority, and optional manual control.

3.4 Transport Energy - This includes wired and wireless distribution of electricity, and portable sources like batteries and stored thermal energy.

3.5 Transport Fluids and Gases - These items require closed containers or fixed piping for delivery. It includes items like water, natural gas, and liquid fuels.

3.6 Transport Data - This includes all types of data in all forms, electronic and non-electronic. Legal rights and money are delivered via data so they are included here.