IT Architecture from A to Z: Theoretical basis. First Edition - Vadim Aldzhanov

Скачать книгу

See Template “TOGAF 9 Template Architecture Definition.doc”

      • Architecture Requirements Specification is a document providing a quantitative view of the requirements, restrictions, suggestions, and measurable criteria that must be met during the implementation of the architecture. See Template “TOGAF 9 Template Architecture Requirements Specification.doc”

      • Transition Architecture. The implementation of the target architecture has several stages. Each intermediate state must be workable and valuable. This document groups projects for each of these stages. See Template “TOGAF 9 Template Transition Architecture.doc”

      • Implementation and Migration Plan is a consolidated implementation plan for projects aimed to achieve the target architecture. It also includes benefits, scope, timeframe, cost, risks, and milestones of projects. See Template “TOGAF 9 Template Implementation and Migration Plan.doc”

      Such set of documents can be done rapidly and in a cost-effective way. If you are going to use third party services, I recommend to include one more document – an architectural contract. This is an agreement between architects and IT project executives. See Template – “TOGAF 9 Template – Architecture Contract.doc” When accepting a project, it will be easier for you to get the desired result if you have agreed on it beforehand.

      Management Strategy

      When forming an IT Strategy, one can determine the strategy on “Technological Architecture” and “Information Systems (Services) Architecture” of some IT infrastructure components, as well as recommendations on choosing solution. To understand the problems of the business and translate them into the IT language, you can use the method of “problem tree – solutions”. As can be seen from the diagram, business formulates its problems in the language of business. The task of the CIO is to translate the business language into a technical language, for the further development of IT projects and setting tasks for the IT department staff In order for business and IT to understand the need to demand from each other, it is necessary to define criteria for achieving goals and objectives, as well as metrics for their measurement.

      “Problem – Solution Tree”

      Financial control strategy

      A financing strategy may foresee an organization’s behavior in IT financing. In particular, it is desirable to have a financial strategy on issues such as:

      • cost of the solution as a priority when choosing an IT project solution, even if it affects the functionality. Solution capabilities must meet business requirements with minimal cost;

      • focusing on the use of free software;

      • balancing by cost or functionality.

      For example, the cost of leasing circuits for different branches of the same bank may differ depending on the distance or geographic location. Let us say that the cost of a 10 Mbps channel (which is a standard and sufficient IT requirement) for a regional branch costs 500 USD. The city branch can get the speed of the channel up to 100 Mbps for the same cost. This branch has a current standard speed of 10 Mbps for about 100 USD a month. The average cost of a communication channel for all branches is about 250 USD. The leadership should have a certain strategy regarding this issue, i.e. provide branches with an opportunity to increase speed within the average cost, maximum cost, or leveling all up to the established channel speed (10 Mbps).

      Outsourcing in the implementation and maintenance of Information Systems and projects should be used whenever possible. The capabilities and potential of the IT department staff should be increased.

      Administrative strategy

      The strategy of changes may foresee the organization’s behavior when changing in requirements, etc. As an example, let’s consider the situation when the number of employees remains unchanged, while the speed of Internet access has dropped significantly due to intensive use. As a solution, the bandwidth can be increased, that will affect the costs accordingly. This issue will periodically occur until it reaches the critical point. Another solution is “repressive” method, i.e. having analyzed the network traffic, the IT department determines that the misuse of the Internet has increased. Some administrative controls may lead to improvement of Internet speed without increasing the costs.

      Strategy of Infrastructure Building

      Architecture choice strategy

      As a solution architecture, one can consider the following:

      • On premise infrastructure;

      • Cloud based infrastructure;

      • Hybrid architecture.

      “On-premise” implies that IT assets are physically located within the organization. Benefits:

      • IT infrastructure is located within the organization and controlled by organization’s IT employees.

      • Relatively low operative expenditures of IT infrastructure.

      • Solution autonomy and higher security.

      Deficiencies:

      • Relatively high capital expenditure in IT infrastructure.

      • The introduction of new services, or surges of existing services are difficult to plan.

      • The need to hire IT specialists to maintain physical servers, network equipment, and so on) leads to additional costs.

      • Indirect costs for IT engineering systems.

      “Cloud based” implies that IT assets are located in the “cloud”.

      Benefits:

      • Relatively low capital expenditure in IT infrastructure.

      • High level of planning of maintenance costs for IT infrastructure.

      • Good communication, linear relationship between the resources used and their cost.

      • Easiness to implement new solutions and expand existing IT services.

      • No need for additional staff.

      • No need for indirect engineering costs.

      Deficiencies:

      • Relatively high operative expenditures of IT infrastructure.

      • Higher requirements for Internet bandwidth and backup channels.

      “Hybrid” architecture provides combined solutions.

      Benefits: The benefits of the first two solutions are used.

      Deficiencies: A higher capital and operative (CAPEX and OPEX).

      Recommendations for selection:

      “Cloud based” solution is more preferable for initial projects, small organizations, organizations with developed geography and so on. “On-site” solution is more preferable for well-developed organizations, financial institutions, organizations where access to the Internet is not a business requirement. “Hybrid” solutions can supplement the IT infrastructure and replace some components of the IT architecture.

      Infrastructure platform choice strategy

      If you choose “On-premises” as deployment infrastructure, there are the following options:

      • Physical servers as a foundation;

      • Virtualization platform as a basis;

      • Mixed infrastructure with no dominance.

      “Physical servers” implies that IT services are located on physical servers. Benefits:

      • Relatively low capital expenditure of IT services for small solutions;

      •

Скачать книгу