WebApp Interface Design - Interface Control Mechanisms and Interface Design Workflow

INTERFACE CONTROL MECHANISM
The objectives of Web application interface are:
- establishing a consistent window into content and functionality provided by interface.
- guiding the users through interactions with web application.
- organizing the content and navigation options.

A metaphor is drawn that guides the user interaction and enables the user to gain understanding of the interface. Some interaction mechanisms available to web application designers are
- navigation menus that list key content and or functionality.
- graphic icons that enable user to select some property or specify a design.
- graphic images that implements a link to content object or the functionality of web application.

INTERFACE DESIGN WORKFLOW
It includes the following tasks:
- The information contained in analysis model is reviewed and refined.
- A rough sketch of web application interface layout is developed.
- The user objectives are mapped to specific interface actions.
- Set of user tasks associated with each action are defined.
- For each interface action, storyboard screen images are developed.
- Input from aesthetic design can be used to refine interface layout.
- User interface objects required to implement interface are identified.
- A procedural representation of user's interaction is developed.
- A behavioral representation is developed.
- Interface layout is described.
- Interface design model is refined and reviewed.

What are different design issues and attributes for web applications?

Design model contains enough information to reflect how requirements are translated into content and executable code. Design should be specific. It is an engineering activity. It leads to a high quality product. the major attributes for quality of web applications are:

- Security of web applications is the ability of WebApp and its server environment to stop unauthorized access or threat.
- Availability plays an important attribute. Availability is the measure of the percentage of time that a web application is available for use. The expectation of a end user regarding the availability of a web application is each and every moment. Using features available on one browser or platform makes the web application unavailable to those who work on different platform or browser.
- Scalability is whether the web application and interfacing systems are able to handle significant variation in volume or will the responsiveness drop. Web application should be designed in such a way that it is able to accommodate the burden.
- Time to market is a measure of quality from a business point of view.

Assessing content quality includes :
- whether the user needs are met by determining the scope and depth of content?
- whether the background and authority of content's authors be easily identified?
- whether it is possible to determine the currency of content, last update and what was updated?
- whether the content and its location stable?
- credibility of content?
- uniqueness of content?
- whether content is valuable to targeted user?
- whether the content is well organized and easily accessible?

Overview of Functional and Configuration Model in analysis for WebApps

THE FUNCTIONAL MODEL
There are two processing elements of web application. The functional model addresses the above two elements of web application:
- user observable functionality delivered by web applications to end-users.
- operations within analysis classes that implement behavior within class.

User observable functionality encompasses processing functions initiated directly by user. These functions are implemented using operations within analysis classes but from end-user point of view, the function is the visible outcome.

The operations within analysis class manipulate the attributes of the class involved as class collaborate with one another to accomplish required behavior.

THE CONFIGURATION MODEL
The web application must be thoroughly tested within every browser configuration that is specified as part of configuration model.
In some cases, configuration model is not more than a list of server and client side attributes. For complex web applications, configuration complexities have an impact on analysis and design.
Client side software provides the infrastructure that enables access to the web application from user;s location.
On server side, appropriate interfaces, communication protocols and related information should be specified if web application has to access large database or inter-operates with other applications.

What is meant by analysis for web applications?

Web sites are complex and dynamic in nature. Web application analysis concentrates on three important criteria:
- information or content that is presented.
- functions that are to be performed for end user.
- behaviors of web applications.

Analysis of web applications is mainly done by web engineers, non technical content developers and stakeholders. Analysis modeling is important because it enables a web engineering team to develop a concrete model of web application requirements. It helps to define fundamental aspects of problem. There are four important aspects that analysis modeling focus:
- Content analysis identifies content classed and collaborations.
- Interaction analysis describes user interaction, navigation and system behaviors occurring as a consequence.
- Function analysis defines web application functions performed for user and sequence of processing.
- Configuration analysis identifies the operational environment in which a web application resides.

Analysis modeling should be done by web applications when the following conditions are met:
- web application is large or complex.
- number of stakeholder is large.
- number of web engineers is large.
- goals and objectives for web application will effect the business.
- success of web application will have strong affect on the success of business.

What are the guidelines to be remembered if In House Web Engineering strategy is chosen for web application development?

Due to the increasing complexity, the web application project becomes like a software engineering project management. It is important to recognize that the guidelines recommended for small and moderately sized WebE projects can be performed quickly. In no case, should WebE planning for projects of this size take more than 5 percent of overall project effort :

- One should understand the scope, the dimensions of change, and project constraints. For an effective WebApp planning, requirements gathering and customer communication are essential precursors.
- An incremental project strategy should be developed so that evolution is not uncontrolled and chaotic.
- Risk analysis should be performed. All risk management tasks are performed for web engineering projects but the approach is abbreviated. Schedule and technology risk is the most important concern for most web engineers.
- The overall project estimate should be developed which focuses on macroscopic rather than microscopic issues.
- A set of web engineering tasks is selected which is appropriate for characteristics of problem, product, project, people on web engineering team.
- A schedule is established in which web engineering tasks are distributed along project timeline for increment to be developed.
- Regardless of project size, it is important to establish project milestones so that progress can be assessed.
- A change management is facilitated by incremental development strategy recommended for web applications. There is a possibility to delay change until next increment which in turn reduces the delay effects that are associated with changes.

What are the guidelines to be remembered if outsourcing strategy is chosen for web application development?

Web applications are outsourced to vendors who specialize in web development. There are some guidelines to be followed while considering outsourcing strategy for the web development:

PROJECT INITIATION :
Before searching for an outsourcing vendor, some tasks needs to be done :
- Analysis tasks should be performed internally.
- Web application audience are identified.
- Overall goals and objectives are defined.
- A rough design of the web application should be developed internally.
- A rough project schedule including delivery dates, milestones dates should be developed.
- Responsibilities for internal organization and outsourcing vendor is created.
- Degree of interaction and oversight with contracting organization is identified.

SELECTING OUTSOURCING VENDORS :
- Interview clients to determine the vendor's professionalism, ability to meet schedule.
- Determining the name of the vendor's chief web engineer.
- Examine work samples of vendor.

ASSESS THE VALIDITY OF PRICE QUOTES AND RELIABILITY OF ESTIMATES:
- Does the quoted cost provide direct or in direct return on investment.
- doe the vendor providing the quote has the professionalism and experience.

UNDERSTANDING THE DEGREE OF PROJECT MANAGEMENT YOU CAN EXPECT:
- It depends on size, cost and complexity of the web application.
- Plans are developed for mitigating, monitoring and managing risks.
- Quality assurance and change control mechanisms are defined.
- Effective communication between contractor and vendor should be established.

THE DEVELOPMENT SCHEDULE SHOULD BE ASSESSED:
- The development schedule should have a fine granularity.
- Tasks and minor milestones should be scheduled on daily timeline.

MANAGE SCOPE:
- Scope changes as web application project moves forward.
- To manage scope, the work to be performed within an increment is frozen.
- Changes are deployed until the next web application increment.

What comprises the Web Engineering Team?

For a successful web application project, there is a need for a successful web engineering team. Web engineering teams can be organized in the same manner as traditional software team, however, players and their roles are quite different.

The roles that people play in a web engineering team are:

- Content is the most important part of web applications. So, role of content developer or provider focus on the generation of content.
- The content developed should be organized. Web publisher is a person who acts as a mediator between the technical person and non technical content developer.
- Web engineer is responsible for activities like requirements elicitation, analysis modeling, architectural, navigational and interface design, web application implementation and testing. He should be thorough in technologies as well.
- Business domain experts take care of questions related to business goals, objectives and requirements associated with a web application.
- Support specialist is a person whose responsibility is to continue with web application support. All the corrections, adaptations and enhancements are taken care by a support specialist.
- Administrator is responsible for the day to day activity of a web application which also includes development and implementation of policies, support procedures, security rights, handling web traffic etc.

In order to build a team for web application:
- team guidelines are established which includes expectations from team member, how problems are dealt and what methods are used to improve the effectiveness.
- strong leadership.
- team motivation and respect for individual talents.
- commitment from every team member is necessary.
- momentum should be maintained.

What are the requirements gathering steps that are used for web applications?

The objectives for web applications are identifying the content and functional requirements and to define the interaction scenarios for different classes of users. To achieve these objectives, following steps are conducted:
- User categories and descriptions are developed for each category by stakeholders.
- Web application requirements are defined and communicated to stakeholders.
- All the information that is gathered is analyzed and then the information is used to follow up with stakeholders.
- The use cases describing the interaction scenarios for each user class are defined.

DEFINING USER CATEGORIES
Understanding the user's background, motivation, and objectives is critical in all software engineering tasks. In order to define a user category:
- one should know the user's overall objective when he or she is using the web application.
- one should know the background of the user and the knowledge of content and functionality of the web application.
- one should know how the user should approach the web application.
- one should know the generic web application characteristics that the user will like or dislike.

COMMUNICATING WITH STAKEHOLDERS AND END USERS
The communication mechanisms that can be used in web engineering work are:
- traditional focus groups.
- electronic focus groups.
- iterative surveys.
- exploratory surveys.
- scenario building.

ANALYZING INFORMATION GATHERED
An evaluation of content objects and operations can be delayed until analysis modeling begins. It is more important to collect information and not evaluating it at this point. As information is gathered, it is categorized by user class and transaction type and then assessed for relevance.

DEVELOPING USE CASES
Use cases tell how a user category will interact with web application to accomplish a specific action. Use cases help the developer to understand the user perception while interacting with the web application, provide detail to create analysis model, help to separate WebE work and provide guidance who test WebApp.

How are web based systems formulated?

The basis of initiating a web application project is firstly, understanding the problem before you begin to solve it and be sure that the solution you conceive is one that people really want and secondly, plan the work before you begin performing it.
Formulation involves a sequence of web engineering actions which begins with identification of needs of business, defining features and functions, performing requirements gathering. Formulation focuses on the big picture; on the business needs and objectives and related information.

Beginning of formulation should be able to answer the main motivation for the web application, the objectives that a web application needs to fulfill and who will be using a web application. While building a web application, it should be build in a single sentence.
There are two type of goals that are identified. First one is informational goals that indicate an intention to provide specific content or information for the end user and second, the applicative goals that indicate the ability to perform some task within the web application.

Once both the goals are identified, a user profile is developed which captures important features that are related to users. Once the goals and user profile is created, formulation focuses on statement of scope for web application.

What are Web engineering Systems? What are the attributes for web based systems?

Web systems deliver complex array of content and functionality to end users. Web engineering creates high quality web applications. Web based systems grow complex, a failure in one can propagate broad based problems. There is a need for disciplined approaches and new methods and tools for development, deployment and evaluation of web based systems and applications.

Attributes for web based systems are:
- A web application should serve the needs of different community of clients.
- A large number of users may access the web application at one time.
- Web application should be able to handle unpredictable load.
- Users of popular web application demand access and availability of them round the clock.
- Web applications uses hypermedia and access information that exists on databases that were originally not a part of web based environment.
- The content should be of good quality.
- Web applications evolve continuously. Continuous care and feeding allows a web site to grow.
- Web applications exhibit a time to market. Web engineers use methods for planning, analysis, design, implementation and testing to compress time schedules.
- To protect sensitive content and provide secure modes of data transmission, strong security measures should be implemented.
- The look and feel of a web application should be appealing.

The categories of web applications that are encountered in web engineering are informational, download, customization, interaction, user input, transaction oriented, service oriented, portal, database access, data warehousing.

Web Engineering Process

Choosing a process model is based on the attributes of the software to be developed.
If immediacy and continuous evolution are the primary attributes of WebApp, a web engineering team might choose an agile process model. If a WebApp is to be developed over a longer time period, an incremental process model might be chosen.

Defining a Framework :
Any one of the agile process models can be applied successfully as a WebE process. Before we define a process framework for WebE, three things must be kept in mind :
- WebApps are often delivered incrementally.
- Changes will occur frequently.
- Timelines are short.

WebE Process Framework :
- Customer Communication : Within the WebE process, customer communication is characterized by :
* Business analysis : It defines the business/organizational context for the WebApp
* Formulation : It is a requirements gathering activity involving all stakeholders. The intent is to describe the problem that the WebApp is to solve.
- Planning : The “plan” consists of a task definition and a timeline schedule for the time period (usually measured in weeks) projected for the development of the WebApp increment.
- Modeling :
Analysis model — establishes a basis for design.
* Content Analysis
* Interaction Analysis
* Functional Analysis
* Configuration Analysis
Design model — represents the key WebApp elements.
* Content design
* Aesthetic design
* Architectural design
* Interface design
* Navigation design
* Component design
- Construction : WebE tools and technology are applied to construct the WebApp that has been modeled.
- Deployment : The WebApp is configured for its operational environment, delivered to end-users, and then an evaluation period commences.

WebApp Engineering Layers

The development of Web based systems and applications incorporate specialized process models, software engineering methods adapted to the characteristics of WebApp development, and a set of important enabling technologies. Process, methods, and technologies provide a layered approach to WebE that is conceptually identical to the software engineering layers :
- Process
WebE process models embrace the agile development philosophy that defines the following activities
* Embrace change.
* Encourages the creativity and independence of development staff and strong interaction with WebApp stakeholders.
* Builds systems using small development team
* Emphasizes evolutionary or incremental development using short development cycles.

- Methods
The WebE methods landscape encompasses a set of technical tasks that enable a Web engineer to understand, characterize, and then build a high-quality WebApp.

* Communication methods : It defines the approach used to facilitate communication between Web engineers and all other Web stakeholders.
* Requirements analysis methods : These methods provide a basis for understanding the content to be delivered by WebApp, the function to be provided for the end user, and modes of interaction that each class of user will require.
* Design methods : It encompasses a series of design techniques that address WebApp content, application and information architecture, interface design, and navigation structure.
* Testing methods : It incorporates formal technical reviews of both the content and design model and a wide array of testing techniques.

- Tools and Technology
These technologies encompasses a wide array of content description and modeling languages, browsers, multimedia tools, site authoring tools, database connectivity
tools, servers and server utilities, and site management and analysis tools.

Attributes of Web Based Systems

Web-based systems and applications deliver a complex array of content and functionality to a broad population of end-users. The following attributes are encountered in the vast majority of WebApps.

- Network Intensiveness.
- Concurrency.
- Unpredictable load.
- Performance.
- Availability.
- Data driven.
- Content sensitive.
- Continuous evolution.
- Immediacy.
- Security.
- Aesthetics.

The following application categories are most commonly encountered in WebE work :
- Informational : read-only content is provided with simple navigation and links.
- Download.
- Customizable.
- Interaction.
- User input.
- Transaction-oriented.
- Service-oriented.
- Portal.
- Database access.
- Data warehousing.