Desired Quality Characteristics in Cloud Application Development Leah Riungu-Kalliosaari

Contents  Introduction  Research process  Findings  Conclusion  Standardization of Cloud Computing

Introduction  Software quality: functional and non- functional requirements  Software quality is an elusive target (Blaine and Cleland-Huang, 2008)  Achieving quality in software requires balancing between many factors e.g. budget, time, communication, outsourcing,

Introduction  Cloud computing: on-demand access to computing resources.  Three service layers: software-as-a-service (SaaS), platform-as-a-service (PaaS), infrastructure-as-a-service (IaaS) (Mell and Grance, 2011)  Cost reduction, increase scalability, improve efficiency  Cloud-based environments for developing and hosting applications  Cloud applications are applications built, deployed and hosted in cloud environments (Hobfield, et. al, 2012)

Introduction  Cloud application development  Pre-defined architectural structures, resources, interfaces, service access and discovery mechanisms.  Emphasis on certain requirements e.g. need for strict conformance, high interoperability

Introduction  Aim: evaluate important product quality characteristics as perceived by organizations developing cloud applications  ISO/IEC  Product quality model: functional suitability, reliability, performance efficiency, usability, security, compatibility, maintainability, portability  Quality in use model: effectiveness, efficiency, satisfaction, freedom from risk and context coverage

Research Process  Research questions  What quality characteristics do developers consider to be important for cloud-based applications?  What activities support developers in achieving these quality characteristics?  Qualitative case study  Grounded Theory for analysis  Five organizations: 1 Large, 1 Medium and 3 Micro

Categories  Five categories  Life-cycle model and tools: describes the software development life-cycle model and the tools used to produce the software.  Waterfall, incremental, agile  Software application: the type of software that the organization is developing. Case ACase BCase CCase DCase E Software application Cloud based test management service (SaaS) Web-based system for managing IT resources Amazon web services-based value adding service for Infrastructure as a Service (IaaS) Cloud-based application for an international social website integrated with the world’s most popular networks (SaaS) Web-based applications

Categories  Important quality characteristics: most desirable aspects of quality  These varied, but usability was common among all the cases  Practices for handling requirements: mechanisms for handling requirements.  Origin: From the developers themselves (Case B, C & D) and from the customer (Case A & E)  Some problems  Case D  Functional system at first  User preferences might affect the built-in functionality.

Categories  Customer involvement: effect of the customer during the development life cycle.  Case A & E: High levels of flexibility to accommodate different customer needs  Case B & C: Customer not involved in developing the first product. Considered customer feedback to improve the applications  Case D: Developing first version, customer not involved, (yet)

Observations  Observation 1: The most important quality characteristics vary among the organizations, but usability was important in all the organizations  Case A: Reliability, availability (quality of service)  Case B: Usability, security when hosting in the cloud  Security as well  data integrity and confidentiality  Conformance to and interoperability with cloud platforms  “Because I'm using the [cloud] APIs … if the security could be breached, then that would first of all break the whole service, and second of all compromise my relationship with the platform [provider]. And that's the key quality issue that I'm worried about before I release the product” – Owner Case C  Usability  All organizations stated usability to be important.

Observations  Observation 2: Agile development methods are preferred when developing cloud-based applications.  Changes in the cloud platforms and user preferences affect the software applications  Agile methods help in reacting to changes, and keeping up with evolving quality expectations  Focus on most important features first  Surprising: Customers more tolerant to errors. (Case C)

Observations  Observation 3: Customer input is valued at different stages of the development.  This depends on where the requirements come from.  From customer (Case A & E): customer is involved from the start  Customers not able to clearly state their needs  From the developers (Case B & C), steady interaction with the customer after releasing the software  Case D expects some changes after releasing the application

Observations  Observation 4: The developers choose development tools according to their knowledge, skills and familiarity with the tools.  Additional tools are chosen based on learnability, usability and appropriateness for the intended use.  Case B: Improve the development process  test management tool  Case C: Cloud APIs  conforming to platform-specific security requirements  Case E: Drupal  appropriate for building web-based applications

Conclusions  Desired quality varied among the organizations  Depends on the application  Usability was important in all cases  Good first impression  Three activities employed to support the development  Selecting a suitable life-cycle model  Engaging the customer  Applying the most suitable tools  Cloud application development is a complex process.  Interaction amongst stakeholders  Requires aligning the development activities with the targeted quality

Standardization of Cloud Computing

 Distributed application platforms and services  ISO/IEC JTC1 / SC 38  WG 1 Web services  WG 2 Service Oriented Architecture (SOA)  WG 3 Cloud computing  Study group on cloud computing   Finnish Standards Association SFS Mirror committee SR310  Chair: Tuomas Nurmela  Secretary: Elina Huttunen (contact at if interested)  Currently 25 members, most active 5-6 persons

Cloud Computing Reference Architecture  The aim of the CCRA is to:  Illustrate and understand cloud services in the context of an overall conceptual methodology  Provide a technical reference to enable the international community to understand, discuss, categorize and compare cloud services  Facilitate the analysis of candidate standards in areas such as security, interoperability, portability and service management and support analysis of reference architecture

Views of the Reference Architecture

Relationship: User / Functional view

Core Roles

Layering of the Functional view