Developing a comprehensive capacity plan can be a daunting challenge at the outset and requires dedication and commitment to maintain it on an ongoing basis. The following hints, courtesy of Informit's IT Management Reference Guide, can help to minimize this challenge.
Helpful Hints for Effective Capacity Planning
- Start small.
Many a capacity planning effort fails after a few months because it encompassed too broad a scope too early on. This is especially true for shops that have had no previous experience in this area. In these instances it is wise to start with just a few of the most critical resources—say, processors or bandwidth—and to gradually expand the program as more experience is gained.
- Speak the language of your customers.
When requesting workload forecasts from your developers and especially your end-using customers, discuss these in terms that the developers and customers understand. For example, rather than asking for estimated increases in processor utilization, inquire as to how many additional concurrent users are expected to be using the application or how many of a specific type of transaction is likely to be executed during peak periods.
- Consider future platforms.
When evaluating tools to be used for capacity planning, keep in mind new architectures that your shop may be considering and select packages that can be used on both current and future platforms. Some tools that appear well suited for your existing platforms may have little or no applicability to planned architectures. This is especially true as more shopsmove toward web-enabled systems.
- Share plans with suppliers.
If you plan to use your capacity planning products across multiple platforms, it is important to inform your software suppliers of your plans. During these discussions, make sure that add-on expenses—the costs for drivers, agents, installation time and labor, copies of licenses, updated maintenance agreements, and the like—are all identified and agreed upon up front. Reductions in the costs for license renewals and maintenance agreements can often be negotiated based on all of the other additional expenses.
- Anticipate nonlinear cost ratios.
One of my esteemed college professors was fond of saying that indeed we live in a nonlinear world. This is certainly the case when it comes to capacity upgrades. Some upgrades will be linear in the sense that doubling the amount of a planned increase in processors, memory, channels, or disk volumes will double the cost of the upgrade. But if the upgrade approaches the maximum number of cards, chips, or slots that a device can hold, a relatively modest increase in capacity may end up costing an immodest amount for additional hardware.
- Plan for occasional workload reductions.
A forecasted change in workload may not always cause an increase in the capacity required. Departmental mergers, staff reductions, and productivity gains may result in some production workloads being reduced. Similarly, development workloads may decrease as major projects become deployed. While increases in needed capacity are clearly more likely, reductions are possible. A good guideline to use when questioning users about future workloads is to emphasize changes, not just increases.
- Prepare for the turnover of personnel.
Over time all organizations will experience some degree of personnel turnover. To minimize the effects of this on capacity planning efforts, ensure that at least two people are familiar with the methodology and that the process is fully documented.
- Strive to continually improve the process.
One of the best ways to continually improve the capacity planning process is to set a goal to expand and improve at least one part of it with each new version of the plan. Possible enhancements could include the addition of new platforms, centralized printers, or remote locations. A new version of the plan should be created at least once a year and preferably every six months.
- Evaluate the hidden costs of upgrades.
Most upgrades to infrastructure hardware resources have many hidden costs associated with them.
Read more on capacity planning at Informit's IT Management Reference Guide.