All the instructions and examples are laid out in each paragraph. I NEED THIS BY 04/25
- Introduction
Instructions: Provide identifying information for the existing and/or proposed automated system or situation for which the SDD applies (e.g., the full names and acronyms for the development project, the existing system or situation, and the proposed system or situation, as applicable), and expected evolution of the document. Also describe any security or privacy considerations associated with use of this document.
The System Design Document (SDD) describes how (1) the functional and nonfunctional requirements recorded in the Requirements Document, (2) the preliminary user-oriented functional design recorded in the High Level Technical Design Concept/Alternatives document, and (3) the preliminary data design documented in the Logical Data Model (LDM) are transformed into more technical system design specifications from which the system will be built. The SDD is used to document both high-level system design and low-level detailed design specifications.
The SDD describes design goals and considerations, provides a high-level overview of the system architecture, and describes the data design associated with the system, as well as the human-machine interface and operational scenarios. The high-level system design is further decomposed into low-level detailed design specifications for each of the systems components, including hardware, internal communications, software, system integrity controls, and external interfaces. The high-level system design serves as primary input to the Preliminary Design Review (PDR). The low-level detailed design serves as input to the Detailed Design Review (DDR).
- Purpose of the System Design Document
Instructions: Provide the purpose of the System Design Document. This document should be tailored to fit a particular projects needs.
The System Design document documents and tracks the necessary information required to effectively define architecture and system design in order to give the development team guidance on architecture of the system to be developed. Design documents are incrementally and iteratively produced during the system development life cycle, based on the particular circumstances of the IT project and the system development methodology used for developing the system. Its intended audience is the project manager, project team, and development team. Some portions of this document such as the user interface (UI) may on occasion be shared with the client/user, and other stakeholder whose input/approval into the UI is needed.
- Design Considerations
Instructions: Describe issues which need to be addressed or resolved before attempting to devise a complete design solution.
- Goals and Guidelines
Instructions: Describe any goals, guidelines, principles, or priorities which dominate or embody the design of the system and its software. Examples of such goals might be: an emphasis on speed versus memory use; or working, looking, or feeling like an existing product. Guidelines include coding guidelines and conventions. For each such goal or guideline, describe the reason for its desirability unless it is implicitly obvious. Describe any design policies and/or tactics that do not have sweeping architectural implications (meaning they would not significantly affect the overall organization of the system and its high-level structures), but which nonetheless affect the details of the interface and/or implementation of various aspects of the system (e.g., choice of which specific product to use).
- Development Methods & Contingencies
Instructions: Briefly describe the method or approach used for the system and software design (e.g., structured, object-oriented, prototyping, J2EE, UML, XML, etc.). If one or more formal/ published methods were adopted or adapted, then include a reference to a more detailed description of these methods. If several methods were seriously considered, then each such method should be mentioned, along with a brief explanation of why all or part of it was used or not used. Describe any contingencies that might arise in the design of the system and software that may change the development direction. Possibilities include lack of interface agreements with outside agencies or unstable architectures at the time the SDD is prepared. Address any possible workarounds or alternative plans.
- Architectural Strategies
Instructions: Describe any design decisions and/or strategies that affect the overall organization of the system and its higher-level structures. These strategies should provide insight into the key abstractions and mechanisms used in the system architecture. Describe the reasoning employed for each decision and/or strategy (possibly referring to previously stated design goals and principles) and how any design goals or priorities were balanced or traded-off.
Describe compliance with CMS Enterprise Architecture (EA) and standards. Specifically identify any deviations that were made from the CMS EA and standards, and provide rationale to support the deviation(s). When describing a design decision, discuss any other significant alternatives that were considered, and the reasons for rejecting them (as well as the reasons for accepting the alternative finally chosen). Sometimes it may be most effective to employ the pattern format for describing a strategy.
Examples of design decisions might concern (but are not limited to) things like the following:
- Use of a particular type of product (programming language, database, library, commercial off-the-shelf (COTS) product, etc.)
- Reuse of existing software components to implement various parts/features of the system
- Future plans for extending or enhancing the software
- User interface paradigms (or system input and output models)
- Hardware and/or software interface paradigms
- Error detection and recovery
- Memory management policies
- External databases and/or data storage management and persistence
- Distributed data or control over a network
- Generalized approaches to control
- Concurrency and synchronization
- Communication mechanisms
- Management of other resources
- Performance Engineering
A contributing factor to System Design will be Performance Requirements.
Performance Requirements are the defined scalability or responsiveness expectations of specific workloads that process on a system.
Instructions:
(a) Using the Performance Requirements defined in the Requirements Document, provide a detailed explanation that describes how the Performance Requirements were incorporated into the systems design. Please refer to Sections 2.0 of the CMS Performance Test Plan and Results Template for guidance on defining Performance Requirements.
(b) Start preparing Production Load Model(s) in preparation for Performance testing. Please refer to Sections 2.1.1 of the CMS Performance Test Plan and Results Template for guidance on Load Model construction.
