Computer for Tax Organization

Technology Consulting

Capacity Planning

I have been watching computersí capacity grow for the last 30 years. In the old days you had to know just how much you were feeding them - the size of your programs and your data stream. Today, capacity is often neglected because the average size of the processors and storage capacity keeps growing. Todayís assumption (or should I say misconception) is that capacity is so large that you donít have to worry about it.

  •Know Your Requirements

Perhaps that assumption holds if your computer is used solely as a stand-alone with no connection to the outside world. However, in business and for personal use we know that this isolation is no longer the case. How many of you have heard of P/C users loading down so much music that they used up their hard drive? How many of you work where the E-mail server is so overloaded that it degrades the system? What about denial of service attack? These hackers know your capacity limits.

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These problems make Capacity Planning needed just as much today as it was when the computer age began. Capacity Planning helps determine the sizing needs of your computer processor and its devices for storing and transmitting data. This process can be quite involved. Thorough planning should integrate analyses of historical trends, forecasts of future workloads as well as considerations for new application systems and changes in business and technological options. The planning can start with the size of the programs to be run and then examine the transmission requirements and data storage needs.


  • Processing Requirments
  • Storage Requirements
  • Communication Needs
  • Current Workload
  • Projected Workload

The Outside World

The sizing needs of the computer processor consist of main memory and its instruction speed which is the rate that a program can be executed. Main memory is measured in RAM, random access memory. This is where the code of a computer program is stored. For example, if you have a database program that requires 50 megabytes of instructions, you will need a processor of greater capacity to properly run the program. The time factor for the execution of the program is measured in instructions per second. This is a standard measure for describing the processorís capacity for executing a given set of machine instructions. In other words, it is how fast a program can be executed.

Analyze Throughput

Through Capacity Planning the computer processor throughput is analyzed. Throughput is the total execution time for all programs (applications) divided by total elapsed time. This can tell you how busy your processor is. There is a direct correlation between the instruction cycle speed and the processorís throughput. The greater the instructions per second speed of the processor is, then the greater the throughput of the computer will be. Knowing that your processorís capacity is sufficient can help increase your processing efficiency and prevent downtime and loss of business.

Inadequate Storage Capacity

Inadequate secondary storage capacity can further degrade your systemís throughput. Obviously, if your computer can readily process everything but has insufficient capacity to store pertinent data, then your companyís service level objectives may not be met. This makes an analysis of disk storage capacity very integral part of Capacity Planning. Such an analysis must look at historical requirements by application and project future needs to serve your customers and meet your business objectives.


For communication purposes planning includes measurement of a lineís capacity in bits per second. The measurement of a switchís capacity may be the maximum number of calls it can switch in one hour or the maximum number of calls it can keep in conversation simultaneously. A sophisticated system user may need to know the measure of the bandwidth of a coaxial cable. Bandwidth is the width of a communications channel often measured in megahertz.

If you are experiencing computer slow downs that are delaying your product deliverables, then Capacity Planning is already overdue. Your best choice is to regularly perform Capacity Planning to prevent computer downtime and loss of business activity.

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