Learning Objectives
By the end of this section, you will be able to:
- Explain systems design principles and networked architecture
- Identify systems designs for enterprise network architectures
The launch of a new company, or the decision to expand an existing business into a new area, are organizational shifts that require new systems. The design of those systems, and their architecture needs, will be most successful when planned using established design principles and best practices. Consider Dr. Singh and the medical office expansion of Hometown Physicians Group. The addition of the new office with the new billing and electronic records system has worked out well. Both offices are functioning as expected, patients can be seen in either location, and patient records comply with current electronic reporting requirements. As part of an outreach effort, Dr. Singh is considering adding a monthly walk-in clinic for vaccinations at the local community center. This would further complicate the system that is currently in place as it is not set up to track nonpatients or to accept government-sponsored health-care programs. The latter capability would need to be addressed and incorporated into the system as the practice can be reimbursed for some expenses through the government-sponsored health-care program. One additional complication is that the program requires specific reports and data to be submitted quarterly through the state health-care program portal.
With these capabilities, Hometown Physicians Group would provide an important service to the community, serve as a source of clinical hours for those studying to be health-care professionals, and contribute to a health-care issue that Dr. Singh is passionate about. To accommodate this new venture, the current system will require additional design work.
System Design Principles and Networked Architectures
After gaining an understanding of the business problem, completing a systems analysis, gathering user requirements, and generating design diagrams to potentially address an organization’s business opportunity, it is time to begin the next phase. The system design process determines and defines the architecture, interfaces, and data for a system that can satisfy the specified requirements. There are several general guiding principles that govern good system design, including:
- Simplicity: Simplifying the design and system solution is preferred as overcomplication can require more work, time, and sometimes leads to solving problems that do not exist.
- Clarity: Designs should be clear and easy to use. Be mindful of users who will interact with the product. What type of experience would an end user want to have while using the product? Avoid or minimize complexity where possible.
- Core functionality: The main or core functionality and its interrelated parts are the most important. Additional system features and details can wait.
- Scalability: Does the solution have the capacity to respond to organizational change—that is, handle additions or reductions of users, clients, products, processes, services, data, as well as an evolving business landscape? Where does the company want to be in the next few years, and how would that impact scalability needs? These considerations should be appropriately addressed within the solution to minimize any constraints on organizational change.
- Reliability: The design and system solution should be reliable when it functions in accordance with its designed specifications, with no or minimal failures during the specified time of its use.
- Security: How secure is the system from external or unauthorized use or threats? A system is deemed secure when authorized users can access it and when all measures to control and safeguard the system are in place.
Ethics in IS
ACM Code of Ethics
All those involved with the systems analysis and design team are expected to maintain ethical standards to facilitate a relationship of trust with the customer. There are eight principles focused on the following: public, client and employer, product, judgment, management, profession, colleagues, and self. These principles were designed to guide decision-making for computing professionals, with a focus on integrity in decision-making and advancing the public good. Just as other professionals such as attorneys and doctors have codes of ethics to protect clients and patients, the ACM code of ethics was established for computing professionals to avoid unjust harm, promote honesty and fairness, and respective privacy to protect customers.
You can find a full description of the Software Engineering Code—ACM Code of Ethics and Professional Conduct at the Association for Computing Machinery’s website.
Network architecture is concerned with the fundamental principles and concepts that underlie the design and operation of a network. The network architecture is a top-level view of the system that defines the equipment in the network and the interaction between the equipment . For example, in your home you might have a printer connected to a network/LAN or the internet. In this case, the network architecture includes your computer/laptop, the printer, the modem, and the router. It could include additional equipment, such as Bluetooth devices or your mobile phone.
The network design, in contrast focuses on the specific implementation and configuration of a network to meet the requirements of a particular organization or application. Network designs can be created using various types of design models and tools. These may include logical and physical designs, prototype designs, or computerized system designs.
Logical and Physical Designs
Designs of systems can be logical or physical, and as these designs are developed, it is important to clearly represent the information presented in both. A logical design illustrates how data is logically presented and flows through the designed system. The focus of logical designs is not on the physical attributes of the design, but on the business needs of the organization and the information gathered from stakeholders about the business problem or opportunity. Logical designs incorporate the business processes needed to visually represent these activities, the flow of data, and the relationships between them—all of which will be later used to create the physical design.
The goal of logical design is to create a high-level representation that is independent of any specific software product. Logical designs can take many forms. One is the entity relationship diagram (ERD), which is a structural diagram used in logical database design that serves as a visual representation of the data flow and its relationship among people, objects, events, places, or concepts. ERD models are composed of entities (something that is definite and uniquely exists, such as a business, college course, or person), attributes (characteristics or traits of an entity), and relationships (interactions between two or more entities).
For example, Figure 4.11 shows an ERD of a doctor’s office. Entities are uniquely identified in rectangular boxes—physician treats patient, physician orders treatment, physician refers to specialist, facility treats patient, and so on—and directional lines with symbols represent the relationship of the connecting entities.
An additional output of the logical design may be the data dictionary, which details the category names and supporting properties of the data used in the database. The dictionary is usually organized in table format, and the general properties for the table may include the column name, contents, number/type of characters, required/mandatory indicator, and any other aspects of the data that support the logical design.
A physical design utilizes the completed logical design to create a concrete, physical system with specific hardware and software components, detailed systems diagrams and layout, and the requirements for each component. Physical designs allow teams to visualize the physical structure of the system and its supporting components and characteristics. During the physical design phase, the data gathered during the logical design phase are input into the tables, columns, indexes, and places where further details can be added. The physical design can be built to optimize query performance, data maintenance, or whatever functions the business needs.
Careers in IS
Systems Designers
Systems designers are specialized professionals who support the analysis and design of information systems. These roles require having technical and analytical knowledge, expertise with software or tools used for documentation, and also possessing communication, leadership, and problem-solving skills. Systems designer roles are generally found in IT departments—with higher-level educational degrees, certifications, and experience contributing to higher salary earnings. Job titles with similar career paths include systems/computer engineer, IS specialist, and software developer. If you are interested in additional information about a career as a systems designer, you can check out the Indeed career guide.
The Data Cycle
The data cycle refers to the different stages that data undergo while they exists in an organization’s system, from its initial generation onward.
- Creation: During the creation stage, the team addresses the different methods by and inputs through which data are created or captured. Data may exist in different formats—such as Microsoft Word, PDF, and SQL—and it is important to identify these data types in considering how to manage this data. For example, your data may enter the data cycle via manual entry wherein authorized users input information directly into the system. Data may also be captured through an import mechanism from an external source. This method is widely used in organizational acquisitions and transitions to maintain the historical components of data and to continue current business processes. The capture may also be generated from other input sources or devices used throughout the organization.
- Storage: Once the data have been created or captured within the system, they need to be stored for future retrieval, use, and reference. The security of the data along with backup and recovery functions are needed to ensure the data are secured and retained for the organization’s use.
- Use: The data usage stage provides an understanding of how the data are used to support business functions. How are the data processed, modified, and saved? Where is the audit trail of data manipulation, and how should it be maintained?
- Sharing: The sharing of system data is another key aspect of the data cycle. The data should be made available so it can be shared internally (in which case, it could include reporting and data analysis purposes) and externally (in which case, it might include sharing data for regulatory reporting requirements).
- Archival: Data archival is the process of transferring data to a nonactive environment for storage, a location other than where the system’s daily use environment exists.
- Destruction: Data destruction is needed as data grows to a volume that is no longer feasible to maintain. Generally, the destruction or purging of data occurs from the archival location, and every copy of the data is removed within the guidelines of the organization’s regulatory retention period.
Prototype Designs
A prototype is a design approach wherein systems designers and users create a small-scale representation or working model of the solution. Prototypes are generally created using an iterative development process, or a series of continuous planning analysis, implementation, and evaluation steps that lead to a design that has increasing functionality and increasingly meets the user requirements. Prototypes also enable users to modify or make interim changes through to the completion of the final product. In addition to the flexibility that prototypes offer, their other benefits include:
- early detection of functional problems
- increased user participation, engagement, and team collaboration
- increased satisfaction with the final product
- greater savings of time and money associated with rework
Creating a prototype does, however, have its drawbacks. Prototypes can be costly to complete and time-consuming to develop. Often, the features included may differ from the final product, and this can be misleading for the stakeholder as it does not provide an end-to-end functioning product. Prototype development also lends itself to rework due to changing business requirements.
Computerized System Design
Use of computers to assist in the design process, including the creation, development, modification, or optimization of design systems is called computer-aided design (CAD). Sometimes called computerized system design, CAD is increasingly used to optimize resources and maximize time to delivery. Designers, engineers, and other technical resources frequently utilize CAD in situations where its ease of visualization, level of detail, capacity for specialization, and ability to optimize products and render a physical product can assist in the design process.
Input/Output Control
In information systems, input/output control falls under the systems design process. An input is the raw data that are processed through the functions of the system. Inputs are controlled by the directives used to submit responses into the system by the user, producing an output according to the system logic. Systems designers create input forms and screens that have quality considerations and that focus on the user experience. These considerations should provide users with the ability to move about the screen to different fields, confirm the accuracy of data entered, and capture the necessary data according to the requirements of its intended use. In Figure 4.12, the inputs of the hiring system (such as résumés and recommendations) are processed according to the system’s logic into an output format (a decision to hire a candidate). The outputs are synthesized through the feedback loop to enhance the hiring process. For example, job performance and satisfaction data are fed back into the system to better analyze potential candidates based on the likelihood of performing well and being satisfied with their job. Certain demographics and experiences as found on the submitted résumés might show a trend in terms of performance and satisfaction. The feedback provided through the system can then be used to better filter potential job candidates and increase the hiring efficiency and possibly reduce turnover.
An output is the information the system delivers to users—in other words, it is the data resulting from the inputs being processed according to the system logic. System designers consider several factors that meet the user requirements. The outputs need to be the right output, quantity, speed, and accuracy. In the hiring example, the output from the system is a candidate to fill the open job position. Other outputs from the system are job performance and satisfaction metrics.
Systems Design Task List
A systems design task list provides a road map through each step of the design process, allowing teams to have an organized workflow and make informed decisions at each step. A well-crafted design system improves the efficiency of teams and improves the speed of product delivery. These guidelines walk through the steps for creating a systems design task list:
- Define and document design processes: Create clear and concise documentation defining the guidelines for system behaviors, standards, attributes, accessibility, and any other relevant information to ensure the design is user friendly and sets team expectations for the end product. Identify the technologies, system elements, and physical interfaces that will comprise the new system. Document the strategy to include a review of the user requirements for the system functionality.
- Identify design characteristics: Define the architectural components relating to the system, ensuring they are able to be implemented. Create a shared language and vocabulary—for example, words, behaviors, images, phrases—to ensure consistency with the design elements as well as consistency within the team’s shared experience in creating a unified user experience. Define and document the design characteristics for each identified component.
- Assess alternative design options and finalize design decisions: Evaluate alternate design options based on similar, parallel, or new developments in theory and practice that may be feasible to implement as an alternative to the identified system. Be sure to include those components at risk of becoming obsolete as the system is being built. Document the rationale for all options presented. Finalize and document the agreed-upon solution to include major hardware, software components, interfaces, subsystems, and dependencies. Revisit the preceding steps and adjust documentation as needed.
- Build and manage the design: Design the solution to include major hardware, software components, interfaces, subsystems, and dependencies. Ensure that accessibility and inclusivity standards are included.
- Review and implement the system design: Review the system design to ensure it meets the approved user requirements, engaging system owners, users, designers, and other stakeholders in the review process. Provide training for all users and system support staff to ensure proper use, support, and maintenance.
- Measure the success of the design system and continue making improvements: Capture user feedback and evaluate the data received using metrics designed to measure its effectiveness and efficiency. Apply continuous improvement processes to address user feedback and system updates and changes.
Systems Designs for Enterprise Network Architectures
The enterprise, a term used to refer to as a business, organization, or company, is composed of a technical network or system of interconnected computers and other devices that allow for the exchange of data and information (such as files) and the sharing of resources (such as printers). Users are connected through devices and communicate via standard internet protocols. The enterprise network architecture refers to the structure and layout of an organization’s network. Enterprise network architecture designs also reference pertinent business functions and provide insight into the overall technical architecture for the business, including the dependencies and connectivity of various applications. The goal of network architecture and its supporting design is to identify the most efficient way to transfer data from one hardware point to the other. Enterprise network architectures are composed of communication protocols along with local area and wide area networks (LANs and WANs), network devices (routers, switches, storage), end endpoints (servers, mobile devices).
There are several ways to design a network architecture, and selecting the right design should be based on the goals and requirements of the network protocol, that is, the set of rules and guidelines that determine how the data are exchanged between network devices. There are two broad types of network architecture: peer-to-peer and client/server. In peer-to-peer (P2P) architecture, the computers on the network are all given the same opportunity to use resources on the network. There is no central server for file storage, and network resources are shared. With client/server architecture—otherwise known as tiered—there is a central computer (server) that operates the network and allocates resources to the equipment connected to the network.
A key characteristic of a peer-to-peer network architecture is its decentralized nature. As shown in Figure 4.13, there is no central server through which the devices communicate directly. Each of the connected devices assumes equal capabilities and responsibilities, hence the term peer. This type of architecture is often used for smaller networks, like those in a home, and are highly resilient—even more than a centralized network—to the compromise of threats.
As shown in Figure 4.14, a client/server network is composed of servers and connected client machines—and thus considered a centralized network. Servers provide services—generally client requests—through their vast processing power. Client/server networks are associated with larger, more extensive computer networks utilizing WANs.
Global Connections
5G Technology’s Global Reach
The fifth generation mobile network, or 5G, is the latest iteration of a global wireless standard. This 5G technology connects people, places, and things, including devices, machines, and objects. It provides increased availability, reliability, and network capacity, allowing for quicker service delivery to users. Increased network capacity allows for the maximum amount of information to be transferred at any given time and considers volume, traffic, utilization, and type of data. 5G became available in 2019 when most phone manufacturers began using the technology commercially. It is widely expected to expand beyond the sixty plus countries currently benefiting from the service, and it is also expected to extend beyond the mobile device industry, spreading into the automotive sector and others as well.