An extensive description of the system requirements, operating environment, architecture, files, and database design may be found in a system design document. Input format, multiple interfaces, output layouts, processing logic, and intricate design are also covered.
A comprehensive set of standards is provided by design systems to enhance and coordinate design activities from beginning to end. But before you can enjoy the advantages of a well-organized design process, you must invest time and energy into creating and maintaining a functional design system.
Although creating a system design document may appear technically difficult, it need not be intimidating if you know what to include and how to format it. This article examines the procedures for producing a successful system design paper.
What is design system documentation?
A design system’s documentation, which includes instructions on how to create its UI elements, components, and design language, acts as an all-inclusive manual for using it. This documentation makes it easier for people to share, use, and put these rules into practice, which helps designers and developers make UIs that are more unified.
A typical design system consists of a component library with processes, numerous components, and UI design elements. Design systems use pattern libraries and style guidelines in this way to provide a seamless and integrated user experience.
In this post, we’ll walk you through all the processes required to write this document and make sure you know what to anticipate from it.
Ensure that you have a proper Introduction
Every document in existence starts with an introduction that gives a system overview and background information. The introduction can be broken up into four sections for more information and structure.
The purpose of the paper is stated in the opening section. It should be stated plainly what this document’s objective is even if it is obvious that it is a system design document. The SDD should first be briefly described before this.
The scope is explored in the second section. Here, the document should go into further detail on how much information it includes about the system’s architecture and how it serves its goal. The in-scope and out-of-scope aspects should be separated into two separate sections in this section.
Addressing the presumptions on which the system should be founded is crucial in the second section of the introduction. These stand for the essential requirements that must be met for the project to be carried out successfully.
The third portion of the introduction should include a thorough description of the process, tools, and methods used in the construction of the system design document, much like important publications like the root cause analysis report. This level of specificity is essential.
The fourth portion of this part should provide a list of all acronyms and abbreviations used throughout the paper so that the target audience can read it with ease. SDD, an acronym for “system design document,” and GUI, an abbreviation for “graphical user interface,” are two frequent examples.
Furthermore, don’t forget to include a section for references while writing the introduction. Essentially, this part should contain a bibliography of important project references and previously created or used deliverables.
Ensure that you are providing a Design Overview
The design overview, which is divided into four components like the introduction, is the subject of the second portion of the system design document. The system overview should be written in a narrative style without using any technical jargon. A high-level system architecture diagram showing subsystems and interfaces with external systems may be included as needed. When appropriate, a high-level context diagram for the systems and subsystems can also be added.
A non-technical description of the system is the main goal of the system overview. The RTM (Requirement Traceability Matrix) in the Functional Requirement Document must also be consulted since it helps determine where functional requirement allocations should be made in the system design document.
The starting point of this section is devoted to background information, thus it is necessary to provide pertinent information about the system. The system’s evolution is the main topic of the second section, which provides succinct details on how it has changed through time.
You must mention the suggested or needed managed environment in the third section. An environment that has been maintained by people and can take many different shapes.
The fourth and last section of the design overview involves listing the restrictions. Here, you should include any general restrictions or limits that have a big influence on your system’s software architecture. Discuss the related software as well in this area.
Any assumptions that the project team made when creating the system design must be included in this section. Mention any trade-off studies that were done, such as resource utilization vs productivity or system incompatibilities.
The system design document should include all relevant constraints, including those related to hardware, software, end-user environments, interoperability, interfaces, and data repositories, distribution and security specifications, network connections, and memory card capacity restrictions. Make sure your system design document has a thorough and in-depth set of restrictions.
Discuss the logical architecture of the design document
Explaining the logical architecture of the system is the third stage in creating a successful system design document. Divide the topic into three sections to address the hardware, application, and communication architectures in order to do this.
Give a thorough description of the hardware and its configuration for the complete system in the “hardware architecture” section. Include schematics showing the connection of each hardware component as well as a comprehensive list of all hardware components with brief explanations. Use subsections for each subsystem as appropriate.
Now pay attention to the application architecture and software development. Focus on the general organization and design of the software, similar to the preceding part. Provide a comprehensive list of the software components, programming languages, and programming tools utilized in the software engineering process. Include a thorough explanation of each item’s purpose in your list as well.
We highly advise using structured organization diagrams to decompose the various segmentation levels when describing the system software. For clarity, make sure that each feature in these diagrams has a reference number and a name.
These diagrams should represent the physical process and data flow and correspond to the logical process and data flow in the FRD’s (Functional Requirement Document) data flow diagrams.
The internal communications construct, which includes all system communications such as LANs and buses, is discussed in the last part under logical architecture, the communication architecture.
Include parts of the intended communication architecture, such as token rings or X.25. Include a diagram to illustrate the communication channels between system and subsystem modules for the target audience. Feel free to add subsections if necessary to improve comprehension.
Discuss the Physical Architecture in detail
In your report, the fourth section should focus on the network architecture. Aim to be comprehensive, covering all aspects related to the physical architecture of the system.
Thoroughly discuss the Data Model
Separate the text into two sections: the first section should deal with database management system files, and the second section should cover non-database management system files. Work along with the database administrator to prepare this part effectively.
Make sure to include both the database and non-database management system files’ final designs. A thorough data dictionary that covers element names, kinds, lengths, validation criteria, data satires, aliases, and descriptions should also be included.
Include a suitable graphic and description in the first subsection that discusses the database management system files. Use normalized table layouts, entity-relationship diagrams, and any other pertinent design data to capture the revised logical model.
Include a thorough physical description of the DBMS records, sub-schemas, and schemas, as well as any other pertinent details. Clarify the access options available to users or the target audience as well. Estimate the size of the DBMS files and the volume of data they contain.
Last but not least, decide how often to update the database’s files, tables, views, areas, and records. This will help you estimate and record how many transactions occur in a database that supports an online transaction-based system.
The non-database management file system is covered in the second portion of the data model, so let’s go through all the non-DBMs and how they are used. Find the records’ record structures, keys, and reference data items.
Additionally, specify the file access method, record length, and an estimation of the file size or data content. Provide an estimate of the update frequency and, if relevant, the predicted number of transactions per unit time for files incorporated into an online-based system, similarly to the preceding section.
The detailed Design must be mentioned next
The hardware, application, and communication detailed designs should each have their own area. This section’s main goal is to give the system development team the crucial knowledge they need to build and integrate hardware components and software modules, forming the links necessary for a usable final result.
To make the creation and acquisition of all system hardware easier, include thorough information about each component needs in the hardware detailed design sub-section. Consider utilizing an appendix or making a separate document reference for comprehensive component documentation.
Include supplementary illustrations and relevant information where appropriate to offer a thorough explanation of each component and its duties. Use proper item names to identify certain manufacturers and follow industry-standard component requirements.
Where appropriate, make sure to provide the following details: power input requirements, connector specifications, cable type and length, user interfaces, monitor resolution, storage and CPU needs, as well as a graphic showing the amount of hardware components.
Focus on the software detailed design as you move on to the application detailed design. Give enough details about the logic and required data to make it easier to write the source code for all system components. You may make the explanation clearer by adding more pictures and pertinent information that explains the structure and operation of each module. Make careful to incorporate any details that provide further insight into the module designs.
Address the communication detailed design in the last subsection. Provide sufficient details about the system’s communication requirements so that they may be built or purchased. The number of servers and clients in each local area network, the specifications for the bus timing requirements and control, the data formats used by the components, and the LAN architecture should all be included.
Next, discuss the External Interface Design
As the name suggests, external systems are not a part of the system that is being developed. Describe the electronic interfaces in this part, with special emphasis on the system’s prospective.
This section should be broken down into two subsections: interface detailed design and interface architecture. Clarify the interfaces between the system being created and other systems inside the interface architecture. Batch transfers and queries may be used using these APIs. Use diagrams to give a clear picture of the communication channels that connect the system to other subsystems.
Discuss the specifications for appropriately formatting, sending, and receiving data through the interface before moving on to the design of the interface in detail. Include descriptions of the queries and the responses, formats for error reports, guidelines for handshaking protocols between the two systems, and specifications for the data formats.
Discuss the Graphical User Interface
Discuss the system’s precise architecture in this part, along with any relevant subsystem input and output for the user. Divide it into four sections: inputs, outputs, navigation hierarchy, and interface design principles.
Consider the input component after talking about the guidelines for interface design. Take pictures of all the input devices that operators use to feed information into the system, such as bar scanners and optical character readers. To prevent edit bypassing, be sure to handle data entry restrictions and incorporate edit requirements for data items.
Describe the system’s output design that the operator uses in the outputs portion. Reports, data presentation panels, and query results are all included in this. Reports should include codes and titles, clear purposes for each output, criteria for dissemination, and any security concerns and access limitations.
Finish this section by going into more detail about the screen and its layout in the last subsection on the navigation hierarchy.
Mention the System Integrity Controls in full details
System integrity control is the focus of the last section on system design document. Understanding that sensitive systems manage data that must not be lost, abused, updated, or accessed without authorisation is essential since doing so might have a negative impact on state operations and violate privacy.
The development of specifications for various levels of controls, such as internal security measures, audit protocols, application audit trails, standard tables, and verification processes governing additions, deletions, and crucial data changes, is therefore imperative. The integrity and security of the system and its data must be protected by these measures.
For a robust design system, comprehensive and unequivocal component documentation is essential, enriching the component library and establishing a single source of truth.
As a fundamental good practice, documentation plays a vital role. It facilitates progress tracking, milestone identification, and learning from both successes and failures. Moreover, documentation enables individuals to comprehend and adhere to the design system effectively.