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Analyzing Business Goals and Constraints of Network Design

Chapter Description

This chapter covers typical network design business goals and constraints and talks about the top-down process for gathering information on goals, and the importance of using systematic methods for network design.

Analyzing Business Constraints

In addition to analyzing business goals and determining your customer's need to support new and existing applications, it is important to analyze any business constraints that will affect your network design.

Politics and Policies

It has been said that there are two things not to talk about with friends: politics and religion. It would be nice if you could escape discussing office politics and technological religion (technology preferences) with a network design customer, but avoiding these topics puts your project at risk.

In the case of office politics, your best bet is to listen rather than talk. Your goal is to learn about any hidden agendas, turf wars, biases, group relations, or history behind the project that could cause it to fail. In some cases, a similar project was already tried and didn't work. You should determine if this has happened in your case and, if it has, the reasons why the project failed or never had a chance to come to fruition.

Pay attention to personnel issues that could affect the project. Which manager or managers started the project and how much do they have at stake? Are there any managers, network engineers, or users who want the project to fail for any reason? Find out who your advocates and opponents are. In some cases, no matter how technically sound your network design is, there will be people who have a negative reaction to it.

Be sure to find out if your project will cause any jobs to be eliminated. Some network design projects involve automating tasks that were once done by highly paid workers. These workers will obviously have reasons to want the project to fail.

Be prepared for the possibility of formidable office politics if your network design project involves the merging of voice and data networks. Voice experts and data experts have traditionally lived in their own worlds. They may face each other with some mistrust and fear for the future. You can often reduce the uncertainty by running short IP telephony seminars for voice technicians and traditional telephony seminars for the data network administrators.

While working with a client, you will gain a feeling for the client's business style. One aspect of style that is important to understand is tolerance to risk. Is risk taking rewarded in the company, or are most people afraid of change? Knowing the employment history of the decision-makers will help you select appropriate technologies. The employment history of the decision-makers affects their tolerance to risk and their biases toward certain technologies. Understanding these issues will help you determine if your network design should be conservative or if it can include new, state-of-the art technologies and processes.

Another aspect of the client's business style has to do with testing the design. At some companies, the testers might claim they have carefully tested a new Voice over IP (VoIP) implementation, for example, when what they really did was get a VoIP call to complete. Your idea of testing, on the other hand, might be to make numerous calls under various load conditions. See Chapter 12, "Testing Your Network Design," for more information on testing.

It is important that you discuss with your customer any policies (religion) regarding protocols, standards, and vendors. Try to learn of any "forbidden technologies" where the users or network engineers have decided, possibly for the wrong reasons, that a particular protocol is slow or unstable.

Find out if the company has standardized on any transport, routing, desktop, or other protocols. Determine if there is any doctrine regarding open versus proprietary solutions. Find out if there are any policies on approved vendors or platforms. In many cases, a company has already chosen technologies and products for the new network and your design must fit into the plans. Ask your customer if there are any policies regarding distributed authority for network design and implementation. For example, are there departments that control their own internetworking purchases? Find out if departments and end users are involved in choosing their own applications. Make sure you know who the decision-makers are for your network design project.

A lot of organizations need to implement policies in response to legal, regulatory, or contractual requirements. In the United States, Generally Accepted Accounting Principles (GAAPs) drive many accounting policies. In the medical profession, network designs may be affected by security and privacy policies that are regulated by the Health Insurance Portability and Accountability Act (HIPAA) of 1996. In other parts of the world, network equipment choices may be regulated by governmental Postal, Telegraph, and Telephone (PTT) organizations.

In the rush to get to technical requirements, network designers sometimes ignore nontechnical issues, which is a mistake. Many brilliant network designs have been rejected by a customer because the designer focused on the lower layers of the OSI reference model and forgot about company politics and technical religion.

Budgetary and Staffing Constraints

Your network design must fit the customer's budget. The budget should include allocations for equipment purchases, software licenses, maintenance and support agreements, testing, training, and staffing. The budget might also include consulting fees (including your fees) and outsourcing expenses.

Throughout the project, work with your customer to identify requirements for new personnel, such as additional network managers. Point out the need for personnel training, which will affect the budget for the project.

In general, it is a good idea to analyze the abilities of the networking staff. How much in-house expertise is there? Should you recommend any training or outsourcing for network operations and management? The technologies and protocols that you recommend will depend on the abilities of internal staff. It is not a good idea to recommend a complex routing protocol, such as Open Shortest Path First (OSPF), for example, if the engineering staff is just starting to learn internetworking concepts (unless you also recommend a comprehensive training plan).

Analyzing in-house expertise is especially important and challenging for companies that merge their voice and data networks. Consider the need to train the traditional voice experts on data technologies and the data experts on voice technologies. Also, implementing voice and video often requires advanced QoS knowledge that may necessitate training.

To ensure the success of your project, determine who controls the network budget—the Information Systems (IS) department, network managers, or users' departments? How much control do users and groups have over network expenditures? Are there any departmental charge-back schemes?

Regardless of who controls the budget, one common network design goal is to contain costs. Reduced budgets or limited resources often force network designers to select the most affordable solution instead of the best solution. It is useful to know the areas in which the network design can be changed with the least effect on performance to meet budget requirements. Chapter 2 discusses typical tradeoffs that must be made to meet the goal of affordability while achieving good performance and reliability.

If possible, work with your customer to develop a return on investment (ROI) analysis for the network design. Make a business case to the customer that explains how quickly the new network will pay for itself, due to reduced operational costs, improved employee productivity, or the enabling of higher revenue potential and market expansion.

Project Scheduling

An additional business-oriented topic that you should review with your customer is the timeframe for the network design project. When is the final due date and what are the intermediate and major milestones? In most cases, management of the project schedule is the customer's obligation, not yours, but you should ask the customer to give you a copy of the schedule and to keep you informed about any slips in the schedule.


It's important to include intermediate milestones in the project schedule. They give you and your client a way to detect slips in the schedule.

Be sure to include circuit disconnect or circuit capacity changes in the project schedule. There is often a long lead time for these changes. Plan to document when the circuit changes and other major changes take place so that if problems occur, you can analyze what has changed to help you troubleshoot.

Many tools exist for developing a schedule that includes milestones, resource assignments, critical-path analysis, and so on. Take a look at these aspects of the schedule and voice your view on whether the schedule is practical, considering what you have learned about the scope of the project. During the technical-analysis stage and the logical- and physical-design phases of the project, be sure to keep the schedule in mind. As you iteratively develop a concrete understanding of the technical scope of the network design project, point out any concerns you have about the schedule.

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