Validation and Verification Testing of ecommerce Applications

Transcription

1 Validation and Verification Testing of ecommerce Applications Bharat Shah, Director of TQM, EqualFooting.Com, Sterling, VA. (USA) Abstract Today, virtually all government agencies, large corporations, hardware and software vendors and other service provider companies throughout the world have started conducting business through Electronic Commerce. But to date, very little effort has been made to verify and validate the way websites are developed and the information is presented. There is a need of studies that examine how Internet based applications are conceptualized, developed, and implemented in order to avoid disrupting users worldwide and also prevent the corruption of central data during interaction with local servers and mainframes. The purpose of this paper is to describe the web application verification and validation effort using new methods and new strategies devised to address the unique phenomenon of the web. The paper describes understanding and applying Web Testing Life Cycle framework for the successful implementation of ecommerce website development project and the methodology followed is based on the software testing principles to ensure that ecommerce requirements are understood and verified properly. The highlights in support of this title include: Emphasis on ecommerce system requirements analysis; Understand validation and verification approach to design, implement and maintain ecommerce websites. Since problems emerge every day, it is impossible to provide a single approach to every website development project. It should be looked at as a reference and framework for those who have not yet begun the process of testing their website. Introduction A great deal of attention is given by IT professionals to deploy a new generation of Internet-savvy business solutions that leverage inexpensive telecommunications services and the World Wide Web Software Verification and Validation (V&V) is a systems engineering discipline, which helps the development organization build quality into the software during the software life cycle. Verification is the process of determining

2 Validation and Verification Testing of ecommerce Applications, Bharat Shah 2 whether or not the products of a given phase of a software development process fulfill the requirements established during the previous phase. Verification typically involves reviews and meetings to evaluate documents, plans, code, requirements, and specifications. This can be done with checklists, issues lists, walkthroughs, and inspection meetings. Validation on the other hand is the process of evaluating software at the end of its development process to ensure that it is free from failures and complies with its requirements. Often this validation occurs through the utilization of various testing approaches and takes place after verifications are completed. The development of any website in general is not complete without rigorous verifying and validating that the implementation is consistent with the specifications. V & V activities are particularly essential in the life cycle of Electronic Commerce (ecommerce) website development projects involving multiple complex transactions from the beginning of the development life cycle. As the complexity of ecommerce websites have increased, it has become necessary to look at V & V as a separate activity in the overall ecommerce website development. Objective The objective of this paper is to describe the Website Verification and Validation Framework model based on the Waterfall Systems Engineering Methodology (Figure-1) for Software Development. Each phase of the Waterfall model is culminated by either verification or a validation activity to eliminate as many problems as possible before proceeding to the next. Upon completing all the phases, this document can serve as a road map for any ecommerce-based project. Some ideas may work as described, but the V & V Analysts will usually need to creatively adapt an idea to their particular ecommerce requirements: A set of recommended test scenarios for each phase provided for the project represent the minimum required scenarios that should be considered to confirm compliance. Specifically, the V & V process should address the following areas:

3 Validation and Verification Testing of ecommerce Applications, Bharat Shah 3 Requirements Analyses - To detect and report requirements errors that may have surfaced during the software requirements and design process; Application Architecture - To detect and report errors that occurred during the development of the website application architecture; Source code - To detect and report errors that developed during source coding; Outputs of the integration process - To ensure that the result of the integration process is complete and correct; Test cases and their procedures and results - To ensure that the testing is performed accurately and completely. ecommerce Overview ecommerce is a platform for selling products and services via Internet. Rather than being a single uniform technology, ecommerce is characterized by a wide range of business operations and transactions, including: Establishment of business-to-business relationship; Electronic payment (using electronic funds transfer, credit cards, electronic cheques, electronic cash); Electronic distribution of products and services; Exchange of information; Pre-and post-sales support; Customer Relationship management (CRM) and Virtual enterprises - groups of independent companies that pool their competencies so that they can offer products or services that would be beyond the capabilities of any of the individual companies. ecommerce applications differ from client-server applications in a number of ways, all centered around a core concept: who, when and what: Who: ecommerce is direct to the customer. There are no set users or training classes or manuals; When: ecommerce availability is real-time 24x7 with response time only dependent on network resources. If system is down or slow, customer won t wait, they will use different vendor;

4 Validation and Verification Testing of ecommerce Applications, Bharat Shah 4 What: Traditional client-server applications are directed at cost reduction and labour-savings. ecommerce applications, on the other hand are revenue-oriented applications, where business partner is marketing and sales. This customer driven ecommerce environment, while advantageous for some applications, can be difficult for conducting online applications such as Online Trading, Online Auctions, Online Publishing, Online Shopping, Online Procurement, Online Billing and Payment with secure transactions. For the purpose of this paper, ecommerce based Online Shopping application is described below. Online Shopping: The most common online shopping model on the web involves using storefronts to sell products. When buying products, the customer browses through the product catalogs, selects the item to purchase and adds it to a shopping cart. Once the customer has finished shopping, the customer pays for the items ordered online using a credit card. After the credit card is approved, the system sends the customer confirmation and the items are shipped to the customer. V & V Framework based on Waterfall Model The development process depicted in Figure-1 is a traditional waterfall model. The design proceeds in a logical sequence of phases or stages. Basically, requirements are developed from the systems need document, and a solution is designed to meet those requirements. The design is then evaluated, transferred to implementation and then to production. Feedback path is provided between each phase of the process and previous phases, representing the iterative nature of software development. Verification activities are conducted at all stages and levels of development. The basis of verification is a three-pronged approach involving tests, inspections, and analyses. Any approach that establishes conformance with a design of an input requirement is an acceptable means of verifying the design with respect to that requirement. Validation activities are a cumulative summation of all efforts to assure that the design will conform to user needs and intended use(s). While testing is always a part of validation, additional validation methods are often used in conjunction with

5 Validation and Verification Testing of ecommerce Applications, Bharat Shah 5 testing, including analysis and inspection methods, compilation of relevant literature and provision of historical evidence that similar designs are safe. The model consists of seven distinct phases: Systems Need, Systems Requirements, Systems Design, Systems Implementation, Systems Integration and Testing, Systems Installation and Acceptance, Systems Operation and Maintenance. A detailed V & V activity for each phase is described next. SYSTEMS ENGINEERING LIFE CYCLE VERIFICATION AND VALIDATION CONCEPT REQMTS. DESIGN IMPLEMTN. INTEG & TESTING INSTALL & ACCEPT. OPER. & MAINT. TRACEABILITY ANALYSIS THROUGHOUT LIFECYCLE CHANGE IMPACT ANALYSIS THROUGHOUT USER NEEDS Systems Need The best intentions and a cool design aren't going to sustain the development and production processes if the concrete statement of the goals and need for the site are missing. Without a clear direction and goals, a web site cannot deliver a consistent, steady message to customers. In this phase, information is gathered for the business need of having an Online Shopping Store. Evaluate the concept and need statement documentation to determine whether the defined concept satisfies user needs and project objectives with respect to the following questions:

6 Validation and Verification Testing of ecommerce Applications, Bharat Shah 6 1. What?: What's the need of the Online Shopping Site? Does business currently do selling to consumers, other businesses, or both? Does business currently have an existing order and payment processing mechanism? Does business currently have hardware and software to deploy a website? What volume of business you expect over the next 1,2,5 years? What are the business risks involved in launching an ecommerce website? 2. Who?: Who are the stakeholders?. Consumer, Cardholder, Issuer, Payment Card, Merchant, Financial Institutions, Certificate Authority and third parties. Review stakeholders' background, their interests, skills, values and knowledge. 3. When? When does business want to launch a website? How often they plan on updating the site - daily, weekly, twice a month, or monthly? 4. Where? Where is the site going to be hosted? Who are the Internet Service Provider (ISP) or Web Service Provider (WSP) for this website?. This kind of evaluation process identifies major constraints of interfacing systems, limitation on the proposed approach and assesses the allocation of system functions to hardware and software, where appropriate. System Requirements The purpose of this phase is to verify the functional, performance, interface, and design requirements for each system element to be developed based on the system needs statement. The minimum requirements for the Online Shopping are identified below:

7 Validation and Verification Testing of ecommerce Applications, Bharat Shah 7 1. The first and most important is the system must be able to present the catalog items with prices and other relevant information correctly; 2. The consumer must be able to generate an order with only the items put into the shopping cart; 3. The consumer must trust the system with their money transaction security and consumer must be able to authenticate the merchant; 4. The system must support shipping mechanism to deliver the items ordered; 5. The system must support existing payment mechanisms, such as checks and credit cards; 6. The system must be able to integrate with current payment processing and financial systems; 7. The system must be user-friendly, fast and efficient. 8. The system must support the expected loads on the server (e.g., number of hits per unit time?), and expected web server and database server performance under such loads; 9. The system must support expected performance on the client side (e.g., how fast should pages appear, how fast should animations, applets, etc. load and run); 10. The development environment must support industry standard HTML specification and targeted browsers; 11. The user interface environment must be consistent for page appearance and/or graphics throughout a site; 12. The system must support real-time maintenance of the website without degrading the performance. Categorize each requirement and verify that: 1. Requirements are not misinterpreted or incompletely defined; 2. Unintended requirements are not incorporated; 3. Requirements are not missed. Verify all requirements based on these general criteria to the level of detail necessary. The analysis must involve the entire system and must define requirements for all subsystems for completeness, consistency, testability, traceability, and

8 Validation and Verification Testing of ecommerce Applications, Bharat Shah 8 technical feasibility. The analysis must also include compatibility with project schedule, funding levels, personnel and other project resources such as communication infrastructure and rollout strategy. Systems Design Designing for the Web is different from designing traditional software user interfaces. There is a sequence of operations that must be executed in a pre-defined order successfully for Online Shopping application to work. Hardware, software, telephone service, security, payment approval service, and Internet Service Provider (ISP) all play a significant role and must be managed all the time. Verify that: Design provides online shopping mechanism; Design includes Browse, Search, Shopping Cart, Order Processing, Credit Card Processing components; Design includes hardware and software required to deploy the website; Design includes website hosting location and communication methods; Design includes integration and interfacing with existing systems (if required)?. Due to the open nature of the Web s architecture and an explosion in the number of online shopping related commercialoff-the-shelf (COTS) products for ecommerce, it is difficult to predict all of the characteristics that the new system will ultimately support. Verify that all chosen components design share the following characteristics: Availability and Reliability: The buyer and seller must have an ability to order and deliver items. This means that the underlying database services and all major components are sufficiently reliable. Scalability: The payment server must be able to process single payment or multiple payments with support for multiprocessor and multi-network installations for future growth. Flexibility: The system must be designed from ground up for enhancements and maintenance. Consistency: All parties involved for payment processing must agree on currency exchange.

9 Validation and Verification Testing of ecommerce Applications, Bharat Shah 9 Isolation: Transactions must be independent of each other. Durability: It must always be possible to recover the last consistent state. Economy: Conducting a transaction should not be expensive. Interoperability: It must be possible to move value back and forth between different systems. System Implementation System Implementation is one of the toughest challenges for V & V Analyst. In general, implementing a successful system has a lot to do with defining the right management process, roles, responsibilities and technical feasibility. However, implementing successful ecommerce based Online Shopping system involves several critical factors. 1. Outlining the transition from paper based ordering to an automated self-service system; 2. Considering the need, both short and long term for dual systems; 3. Reviewing user and security issues; 4. Managing the integration of internal legacy systems with the new web-based payment processing system including links to financial systems; 5. Anticipating technical and cultural barriers and developing a roll-out plan to overcome any objections; 6. Measuring what conditions or actions will determine the implementation process. Here is a high-level view of the methodology that V & V analyst must use: 1. Decompose each function described in Systems Design Review (SDR) document into logical services such as user interface, web interface, business rules and data; 2. Identify workflow and interactions between these services.

10 Validation and Verification Testing of ecommerce Applications, Bharat Shah 10 Code and all new documentation are also the candidates for inspections during this phase. Code inspections should check for technical accuracy and completeness of the code, verify that it implements the planned design, and ensure good coding practices and standards are used. Code inspections should be done after the code has been compiled and all syntax errors removed, but before it has been unit tested. Documents should be inspected for accuracy, completeness, and traceability to higher-level documents. System Integration and Testing V&V test Planning is a major portion of V & V test activities and spans several phases probing for errors and weakness that reveal hidden faults. The final version of the Acceptance Test Plan should be inspected to detect defects in the definition of test cases and to verify that each test case will verify the requirements with which it is associated. Test case and test procedure inspections should verify that they are in accord with one another and with the Acceptance Test Plan. These inspections should verify that the test cases and procedures will execute properly and correctly, and that all needed data are available. Potential inspectors are representatives from any of the life cycle phases before or after this one. Effective testing requires a comprehensive understanding of the system, analyzing the system concept, requirements, design and code. As part of V & V activity, develop test matrix identifying all system functions defined within the requirements. Conduct testing across a variety of platforms in order to ensure that potential users of the website are able to adequately access the site. At a minimum, testing must be performed for each operating system individually with at least three browsers (IE, Netscape & AOL). Test cases must be prepared for each desired test scenario. Depending upon the number of functions and scenarios that are applicable to the web page component and type of test, several test cases will be required to successfully complete the test. Test cases should be carefully selected to keep their number small yet still include those functions that would most likely cause website functionality problems.

11 Validation and Verification Testing of ecommerce Applications, Bharat Shah 11 Typically, website must be tested for the following general criteria: Unit testing of individual page components and layouts to ensure that they behave according to specifications; Link testing to check for link between local web pages and remote websites; System testing, which tests the entire website for performance, functionality, defects and faulty interactions to ensure that the entire system functions correctly as a whole; Integration testing, where the website application installed on the web server is tested to ensure that it performs as specified and does not cause adverse impacts on other website applications, and is compatible with other systems in the computing environment; Acceptance testing, to ensure that the Internet application developed meets the business requirements. System Acceptance and Delivery The formal acceptance procedure is carried out during the acceptance and delivery phase. At a minimum, perform a requirements-driven demonstration of the software to show that it meets its requirements. The phase also may include other arrangements that are intended to assure that the software will function correctly in its intended environment. Conclusion This paper provides a broad framework of the Web Testing life cycle for ecommerce based Online Shopping application. Although the methodology steps are presented in a sequential fashion, experience has shown that many of the activities are actually cyclic with extensive feedback between activities and/or concurrent. Implementers should not enforce a strict waterfall approach to the steps given. Not only may variations in the order of the activities be appropriate, but also it is frequently necessary to revisit previous activities as the test requirements and design become more mature. The methodology given here must be tailored to each specific test implementation.

12 Validation and Verification Testing of ecommerce Applications, Bharat Shah 12 References Systems Engineering Framework for ecommerce Websites, Bharat Shah, Paper Presented at International Council on Systems Engineering Conference (INCOSE 2000). A Framework for Year2000 Compliance Testing of Internet Based Applications, Bharat Shah, Quality Assurance Institute, April Software Verification and Validation. Roger Fujii. NIST Special Publication Creating stores on the web. Joe Cataudella, Ben Sawyer, Dave Greely. Building the E-Empire, Steffano Korper & Juaniti Ellis. Independent Verification and Validation Options published by U.S. Department of Health and Human Services Anchoring the Software Process, Barry Boehm, USC, IEEE Software, July 1996) BIOGRAPHY Mr. Shah has over 19 years of information systems development experience across a broad base of application architectures, Internet and information technologies. Mr. Shah is currently working as Director of Total Quality Management at EqualFooting.COM a B2B marketplace in Virginia, USA. Mr. Shah holds B.Tech degree in Chemical Engineering from Indian Institute of Technology, Kharagpur and has published many papers in conferences and journals in the areas of Website Development and Testing. Mr. Shah can be reached via at bharatshah@equalfooting.com.