CPD&M uses functions as the basis for identifying and managing technical risk and creating a Design Guide. This Quick Guide illustrates the trail of Functional Analysis all the way through a generic CP development process within a development project until a complete Design Guide emerges at the end of the project. Note that your Phase-Gates may be different.

Phase 1:

• Identify and document NUD Functions the Customers and Stakeholders need. These are technology "pushes", or needs that are defined as "pulls" from customers. This information is typically gathered from customer interviews using a Customer/Stakeholder Interview Guide.
• Group, rank and prioritize NUD Functional Need Statements in an Affinity/KJ Diagram.
• Translate, rank and prioritize NUD Customer Functional Needs into NUD technical requirements that are measured as Functions that the new technology or product must be capable of performing as measured by The Big 7 CP Metrics. Use QFD and the Houses of Quality to conduct this work.
• Document the NUD Functional Requirements in the System Requirements Document (SRD). They are assessed and validated in the System Requirements Review (SRR). These deliverables enable Gate1.

Phase 2:

• Refine and further define the specific Functions the design(s) must perform to meet requirements.
• Once a final Design Concept has emerged from the Pugh Process, document the maturing list of Functions in a Function Tree based upon the concept's physical architecture. This is a hierarchical illustration of the cascading Functions from the System Level down through Subsystems and Subassemblies, commonly referred to as a System Functional Architecture.
• Convert the Function Tree into a Functional Flow Diagram with the Functions being laid out as a serial/parallel flow diagram illustrating interrelationships as mass, energy and information flows over time.
• Create Design Failure Modes & Effects Analysis (DFMEA), Noise Diagrams, and Fault Tree Analysis (FTA) on all the NUD Functions. The FTA evaluates the "domino effect" that a failure has on the integrated system once the elements of the Noise Diagrams and DFMEA are understood.
• Develop a set of Design Controls based on the risks identified in the DFMEA, Noise Diagrams and FTA. Design Controls include Computer Aided Engineering Modeling & Simulation (CAE M&S), CAD, Base-line Y as a function of controlling Xs Characterizations, physical proto-type Design of Experiments (DOEs), and Verification/Validation (V/V) Tests on demonstration models.
• Prepare Base-line Parameterization of the detailed designs based on the foundation of Functional Analysis and Risk Identification. Construct Input-Output-Constraint (I-O-C) Diagrams, Base-line Parameter Diagrams, and refined/updated Noise Diagrams for each NUD Function within the design's architecture to enable this work. These help illustrate the candidate Critical Parameters.
• Use these documents to pass the System Functional Review (SFR) and then the Preliminary Design Review (PDR) in preparation of deliverables for Gate 2.

Phase 3:

• Use all appropriate Design Controls (CAE M&S, Y-X Characterization and physical DOEs) iteratively to mature the Functions (Ys) by developing the controllable parameters (Xs) to meet nominal performance requirements in light of the first 5 metrics of The Big 7 CP Metrics. The result is measurable, stable, adjustable sub-level designs. The controllable parameters (Xs) that are independent, interactive, and have a hyper-sensitive impact on Ys will be known. The statistical significance of the Xs will also be understood.
• Focus the Design Controls (CAE M&S and physical DOEs) on making the NUD Functions "robust" to NUD Noises identified in the Noise Diagrams. The result is measurable, stable, adjustable, robust and capable sub-level designs to meet objectives and results for Gate 3.

Phase 4:

• Use all appropriate Design Controls iteratively to mature the Functions (Ys) by developing the controllable parameters (Xs) to meet integrated nominal performance requirements in light of the first 5 metrics of The Big 7 CP Metrics.
• Focus Design Controls (CAE M&S, physical DOEs and V/V Tests) on making the NUD Functions across the integrated system "robust" to NUD Noises identified in the integrated set of Noise Diagrams (Integrated Noise Map for the system). The result is measurable, stable, adjustable, robust and capable System Functions. The controllable parameters that are independent, interactive, hyper-sensitive and statistically significant for meeting the System Requirements are known. The learning is summarized and the Design Guide is finalized, meeting Gate 4 Requirements.

 

CPD&M Focuses on Functions

Once a Functional Flow Diagram is fully illustrated and the NUD Functions highlighted, an Input-Output-Constraint (I-O-C) Diagram can be constructed. An I-O-C Diagram illustrates the Mass, Energy and Information Flows coming into and out of a specific Function. These are based upon the Laws of Conservation of Energy and Mass. They are used to enhance the detail in a Functional Flow Diagram so that it is clear what forms and types of Mass, Energy and Information are entering and leaving each Function over time. I-O-C Diagrams are very useful on New Functions because they are in need of complete definition, as they are totally new and have little or no existing detailed description. This is always true of New Technologies that have just been invented.

 

I-O-C Diagram Template