Home > Articles > Software Development & Management > Architecture and Design

Like this article? We recommend

Applying Perspectives to Views

Although the views, when combined, form a representation of the whole architecture, we can consider them largely independent of one another—a disjoint partition of the whole architectural analysis. For any significant system you usually have to partition your analysis this way, because trying to address the entire problem is too much to understand or describe in one go. However, many architectural decisions address concerns that are common to many or all views. These concerns are normally driven by the need for the system to exhibit a certain quality property rather than to provide a particular function. In our experience, trying to address these aspects of an architecture by using viewpoints doesn't work well. Consider security, as an example:

  • Most systems need the ability to identify and authenticate users (internal and external, human and mechanical). Security processes should be effective but unobtrusive, and any external processes exposed to the outside world need to be resistant to attack.
  • The system must be able to control different classes of access to information and may need to apply these controls at varying levels of granularity (for example, defining object-level security within a database).
  • The system must be able to maintain and distribute secret information (such as keys and passwords) and must be up to date with the latest security updates and patches.

These security considerations need to be considered in the Functional view, Information view, and Operational view of the system, respectively. Rather than defining another viewpoint and creating another view, we need some way to modify and enhance our existing views to ensure that our architecture exhibits the desired quality properties. We therefore need something in our conceptual model that can be considered "orthogonal" to viewpoints, and we've coined the term architectural perspective (which we shorten to perspective) to refer to it. An architectural perspective is a collection of activities, tactics, and guidelines that are used to ensure that a system exhibits a particular set of related quality properties that require consideration across a number of the system's architectural views.

With perspectives, we're trying to systematize what a good architect does anyway—understand the quality properties that are required; assess and review the architectural models to ensure that the architecture exhibits the required properties; identify, prototype, test, and select architectural tactics to address cases when the architecture is lacking; and so on.

A perspective provides a framework to guide and formalize this process. This means that you don't work with perspectives in isolation, but instead use them with each view to analyze and validate the qualities of your architecture and to drive further architectural decision-making. We describe this as applying the perspective to the view, as shown in Figure 2.

Figure 2

Figure 2 Applying perspectives.

Why Perspectives Are Important

Applying a perspective helps you in three crucial ways.

First of all, applying a perspective almost always leads to the creation of something that provides an insight into the system's ability to meet a required quality property. Such a model demonstrates either that the architecture meets its required quality properties or (more likely in the early stages of architecture definition) that it' deficient in some way. These insights normally drive further architectural design activity and are usefully recorded in their own right as rationales for significant design decisions.

Second, applying the perspective often tells you that the architecture will not meet one of its quality properties, and helps you to identify the required architectural improvements. In this case, you may need to change an existing model in the view, create additional models to further develop the content of the view, or perhaps do both of these.

Finally, some of the models and other deliverables created as a result of applying a perspective will be of only passing interest and will probably be discarded once the insight or improvement they reveal is understood. However, other outputs of applying a perspective are of significant, lasting value and supply important architectural information. These outputs, which we term artifacts, are a valuable outcome of applying a perspective and should be preserved. Artifacts are typically captured as documents, models, or implementations, which are referenced from the AD as supporting information.

Perspective Catalog

A perspective catalog defines a number of perspectives, which the following table briefly describes. The perspective catalog aims to identify all of the quality properties that may be important to a modern information system. Some will be more relevant than others, depending on the goals of the system, the context in which it's being built, and the concerns and priorities of the stakeholders.

Perspective

Concerns

Accessibility

Ability of the system to be used by people with disabilities

Availability and Resilience

Ability of the system to be fully or partly operational as and when required and to effectively handle failures that could affect system availability

Development Resource

Ability of the system to be designed, built, deployed, and operated within known constraints around people, budget, time, and materials

Evolution

Ability of the system to be flexible in the face of the inevitable change that all systems experience after deployment, balanced against the costs of providing such flexibility

Internationalization

Ability of the system to be independent from any particular language, country, or cultural group

Location

Ability of the system to overcome problems brought about by the absolute location of the system's elements and the distances between them

Performance and Scalability

Ability of the system to execute predictably within its mandated performance profile and to handle increased processing volumes

Regulation

Ability of the system to conform to local and international laws, quasi-legal regulations, company policies, and other rules and standards

Security

Ability of the system to reliably control, monitor, and audit who can perform what actions on which resources and to detect and recover from failures in security mechanisms

Usability

Ease with which people who interact with the system can work effectively

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.

Overview


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information


To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.

Surveys

Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.

Newsletters

If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information


Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.

Security


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.

Children


This site is not directed to children under the age of 13.

Marketing


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information


If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.

Choice/Opt-out


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information


Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents


California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure


Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.

Links


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact


Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice


We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020