Delphi method is a structured communication technique (or process) developed to be systematic and interactive with an iterative component that relies on a panel of experts. The experts are preselected based on predefined criteria; each answers questionnaires or completes pairwise comparisons of an HDM model in two or more rounds. After each round, a facilitator provides an anonymized summary of the experts’ judgments in a result table. Results from the previous round are provided as well, as are the reasons for the judgments [2].
Experts are encouraged to revise their earlier answers after considering the replies of the other members in the panel. The objective during this process is to decrease and converge towards the “most reasonable” answer or judgement. Finally, the process is stopped after a predefined stop criterion, e.g., number of rounds, achievement of consensus, or stability of results (i.e., reduced inconsistency level).
The Delphi method is based on the principle that decisions from a structured group of individuals are more accurate than those from unstructured groups. The technique can also be adapted for use in face-to-face meetings; it is called the mini-Delphi. The Delphi method has been widely used for business forecasting, which is commonly used among fund managers and stock picking analysts and has certain advantages over another structured forecasting approach.
There are four key characteristics to implement a successful Delphi technique:
(1)Anonymity of the participants;
(2)Structuring of information flow;
(3)Regular feedback;
(4)Role of the facilitator.
4.3.Cloud computing models
Cloud-computing providers offer services in three main different models: IaaS, PaaS and SaaS, which are often portrayed as being layers in a stack. However, such an understanding should not lead to the misconception that these platforms need to be implemented in coordination or in an order.
Thus, it is common to implement the SaaS without using the underlying PaaS or IaaS layers. It is also equally possible to run a program on IaaS and access it directly, without wrapping it as a SaaS [3].
The following definitions are based on The NIST Definition of Cloud Computing:
•“Software as a Service (SaaS). The capability provided to the consumer is to use the provider’s applications running on a cloud infrastructure. The applications are accessible from various client devices through either a thin client interface, such as a web browser (e.g., web-based email), or a program interface. The consumer does not manage or control the underlying cloud infrastructure including network, servers, operating systems, storage, or even individual application capabilities, with the possible exception of limited user-specific application configuration settings.
•Platform as a Service (PaaS). The capability provided to the consumer is to deploy onto the cloud infrastructure consumer-created or acquired applications created using programming languages, libraries, services, and tools supported by the provider. The consumer does not manage or control the underlying cloud infrastructure including network, servers, operating systems, or storage, but has control over the deployed applications and possibly configuration settings for the application-hosting environment.
•Infrastructure as a Service (IaaS). The capability provided to the consumer is to provision processing, storage, networks, and other fundamental computing resources where the consumer is able to deploy and run arbitrary software, which can include operating systems and applications. The consumer does not manage or control the underlying cloud infrastructure but has control over operating systems, storage, and deployed applications; and possibly limited control of select networking components (e.g., host firewalls).” [3]
5.HDM Model
The HDM model (see Figure 2) was developed using four levels of criteria—Mission, Objectives, Criteria and Strategy. The explanation and rationale for choosing these criteria are as follows.
5.1.Mission
The “Mission” of this HDM model is to “determine the model of cloud service strategy for our company”. In this specific scenario, a mid-size fashion company is looking to move its IT operations to the cloud. While this mission is specific to a fashion company, this model could be applied to any business where different experts would be required.
Figure 2.Team 1 HDM model.
This mission is a common scenario many businesses face, where there are pros and cons to moving their IT infrastructure from in-house to the cloud. There are many cloud service options a company must evaluate and this model is designed to aid in choosing which cloud service model a business should move its operations to. This model does not recommend any specific cloud service provider, though it does recommend choosing one of the three cloud service options (SaaS, PaaS or IaaS). Additional models would be required to choose a specific provider.
5.2.Objectives
The HDM model consists of four criteria (see Figure 2): Technical, Security, Economic and Management. Objectives were chosen based on a thorough analysis of expert opinions and literature reviews. When a business is looking to move its services to the cloud, they are looking for specific benefits to the company. Examples include increased focus on business, faster time to market, increased business agility, reduced operational costs, and lower development costs. These four objectives cover all the concerns and objectives a company must consider when moving its IT services to the cloud. It is important to note that additional objectives were evaluated and considered by the team. These four objectives were deemed to be the most important objectives a company must evaluate. Due to time limitations on the scope of this project, no more than four objectives were added to the model. More objectives could be added to future models, for example, Political.
1.Technical objective: Evaluating technical considerations when deciding to move operations to a cloud service.
2.Security objective: Evaluating security considerations when deciding to move operations to a cloud service.
3.Economic objective: Evaluating financial considerations when deciding to move operations to a cloud service.
4.Management objective: Evaluating business/management considerations when deciding to move operations to a cloud service.
5.3.Criteria
The criteria in Figure 2 consist of two criteria per objective. Due to time limitations on the scope of this project, no more than two criteria per objective were added to this model. The original model consisted of four criteria per objective. To narrow this down to only two expert opinions, a literature review was used to reduce the number of criteria by 50%.
1.Technical
