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Getting Started With Capacity Management

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I’m often asked when running ITIL® training courses how to set up a particular process or function, and Capacity Management crops up on quite a regular basis. Maybe because the process seems so big or disjointed that all too often, that phases people. Here are some ideas, some my own and some extracted from industry experts who have engaged with me in the past. They have become somewhat merged, so if you spot your words of wisdom embedded herein, let me know and we’ll add a salutation.

I hope they will assist you to get started, or maybe improve on what you currently have in place.

If you are about to say "I don’t need to as all my infrastructure is in the cloud", then remember that the cloud is really just somebody else’s computer with capacity limitations… and what about all of those desktop and mobile devices and network infrastructure?

So How Are You Actually Going To Manage Capacity And Performance?

To some extent it depends on what platforms you are using, so firstly you need to look at things from a strategic level and consider how your IT department actually connects with and underpins your company’s business activities. Such as, what business actions effect your capacity and performance, and how you can track them both. It’s not all about the technology of course but we’ll get to that later. Firstly you will need to connect with the people who know the most about business activities, because you will need to fully understand the process and how it will grow in the future.

Getting Started With Capacity Management

Key Process Interfaces

Capacity Management does not stand alone as a process. There are a number of ITIL® processes that go hand in hand, like incident and problem management ITIL, also change, configuration and release management. In the case of Capacity Management the partner processes are Availability, IT Service Continuity and Security. Together with Capacity Management they are known as the processes that underpin the ‘warranty element’ that make a service ‘fit for use’ and help to provide ‘Service Value’. We tend to see them documented in detail in our Service Level Agreements (SLAs).

Availability Management though is the closest, almost like a sister process to Capacity Management, with availability looking at services from an overall uptime perspective, while Capacity management is concerned with the capacities involved. While both are vital, Capacity Management underpins availability because unless there is sufficient capacity, you won’t have availability, hence availability and capacity plans should be produced in conjunction with each other. Organisations often delegate capacity and availability to a single role or team to ensure this close integration.

Operationally Capacity Management ensures that the current IT capacity is optimised in all areas of concern, in a cost-justifiable manner, and with one eye toward future requirements.

For example, suppose a database is growing by 2 GB of disc storage every week, and the free space on the hard disk is 100 GB. It would take around 50 weeks for the limit to be breached. The capacity is sufficient as of today, and needs to be tweaked before the 50th week comes around. You will need to understand the lead times for new storage and cost involved. You will also need to allow time for planning and installation of the additional capacity. The analysis surrounding capacity forecasts, and ensuring no mishaps take place because of capacity issues, is proactive Capacity Management process in action, as opposed to waiting for a capacity related incident to be reported and then having to take a reactive and unplanned action to add more capacity.

Getting Started With Capacity Management

Interface With Demand Management

Capacity Management (specifically the business capacity management sub-process) interfaces with the Demand Management process, in fact some would argue that they are part of the same process. Demand management feeds the business information necessary to carry out capacity management activities. Likewise, business capacity management provides inputs on where capacities can be optimised and influence demand - to ensure that the available capacity is not wasted.

Understanding where demand comes from and when peak demand occurs is the responsibility of Demand Management, we call these peaks and troughs in demand ‘patterns of business activity’ and they may occur on a daily, weekly, monthly or on an annual basis, or even seasonally or due to specific events like Bank Holidays. They may even be weather related. This demand data is then fed into Business Capacity Management.

Equally, Business Capacity Management provides data to demand management on idle, peak and troughs of capacities, who work closely with each other to optimise and in some cases, create demand to fill the troughs and balance demand to a certain extent.

Getting Started With Capacity Management

So Back To Getting Started With Capacity Management

Firstly it’s worth saying that Capacity Management is not just about tools A Capacity Management solution is going to involve a combination of tools, processes and people. Ideally start with process (based on ITIL®), spend the majority of your budget on people and try to get the tools as cheaply as possible… negotiate… because they aren’t cheap.

From the outset you will also need to establish a common understanding of Capacity Management. Resetting of expectations and education about what Capacity Management can reasonably provide is critical to all stakeholders from the early stages right through into the run phase.

The ITIL® process going strictly by the book is huge. Like testing, you could throw an unlimited amount of money and resources at it and still not finish it, and still get caught out with capacity issues, so as they say “don't try and boil the ocean”. Start with the basics, work out what you want from it and prioritise. You will never get all the resources you need, the intelligence (people/skills), and the budget to get capacity management to CMMI level 5. So work out where Capacity Management can really add value, and make that your starting point.

Getting Started With Capacity Management

The 3 Sub-Processes Of Capacity Management In More Detail

Capacity Management is a complicated process. It has three sub-processes: component capacity management looks at it from individual component level, service capacity management from a service level and business capacity management from an overall business perspective.

1. Component (Resource) Capacity Management - Components are individual infrastructure elements of IT service, like hard disks, network bandwidth, processors, workstations, network connections, etc. One of the prime objectives of component Capacity Management is monitoring components to ensure that sufficient capacity is on hand to perform the respective functions optimally. Forecasting future component requirements plays into this as well.

By forecasting future capacities, component Capacity Management can prevent capacity-related incidents, thereby reducing downtime.

It may not always be about adding additional infrastructure when you need more capacity. There are tuning techniques that can leverage the existing infrastructure to meet future requirements. Let’s say there are two servers your organisation. Whilst one is mostly overloaded, the other is relatively free. You can share the load between the two servers by monitoring various technological components, optimizing the usage by tuning them appropriately, predicting future capacities and preventing capacity related incidents.

(Click this link if you want to learn about our monitoring and event management training).

2. Service Capacity Management - IT services include email, Internet, telephony, blackberry messaging, etc. In the previous sub-process, we looked at the capacity levels of individual components - servers, routers, switches, et al. Service Capacity Management involves doing a similar set of activities across a service. So, on an email service, the Capacity Management objective is to ensure that there is sufficient capacity for the email service to function normally. This may translate into drilling down to individual servers, gateways and load balancers, and ensuring that their capacities are fine-tuned to provide overall optimum capacity for the service.

Generally, service level agreements (SLA) deal with service capacities, and not component capacities. Once your service capacity is defined, component capacities are to be aligned to meet your service requirements.

Monitoring and recording capacities of components and services requires specialised, expensive tools. Because of this, larger enterprises have an edge over the smaller ones in implementing Capacity Management.

Service Capacity Management involves monitoring end-to-end service capacity against the agreed SLA. You report breaches if they are any and forecast possible issues by analysing the changes going into a service.

3. Business Capacity Management - Business Capacity Management isn’t about monitoring the capacity of the business processes to follow suit with the other sub-processes. Instead, this process is linked to the demand that comes from the business and ensuring that the supply is in place when the business needs it.

This sub-process directly aligns IT with business, and acts as a feeder for service and component Capacity Management processes.

The main objective of business Capacity Management is to ensure that future business requirements are translated into quantifiable IT services. It’s also involved in designing, planning and implementation of the service on time.

Business Capacity Management requires understanding service level requirements from the capacity perspective, interpreting the capacity requirements for services and component Capacity Management processes, assisting with agreeing SLAs, designing, amending and implementing service configuration and controlling major changes done to services

Getting Started With Capacity Management

Getting The Process Off The Ground - Documented And Implemented

As with most processes but especially for Capacity Management, you need to:

  • Identify your stakeholders
  • Work out "What" you want Capacity Management to do
  • Define your limitations (risks, issues, costs, etc)
  • Set your objectives
  • Work out "How" you are going to achieve your objectives. List your activities and their cost
  • Define the roles and responsibilities
  • Define how and what you are going to measure
  • ITIL®’s Capacity Management process is so large that it would be foolish for a capacity manager role to take it all on. Some of that can be approached by delegating certain roles to architects, subject matter experts, and day-to-day BAU operations roles. It can all be in the Capacity Management process but delegated. So try not to get sucked into the day-to-day tuning activities, leave operations/tech areas to do that.

Specifically for Capacity Management you will also need to ensure that:

  • Your performance thresholds are set
  • Event management is doing its job properly
  • You have monitoring and data collection in place within your environment
  • That you are planning and reporting
  • This will ensure that you won’t incur incidents from running out of disk space on a daily basis. Capacity Management will be blamed for that but it is really an operational Capacity Management activity. It needs to be managed, but you don’t need to do everything capacity related…It's a team effort.

So like other processes, Capacity Management is not the sole responsibility of the 'Capacity Management team' but needs the active involvement of other roles. These people will need engaging in order to manage their expectations and make sure they understand the importance of their involvement. Without them being on board, Capacity Management will need to revert to a series of analysis reports and plans with insufficient inputs and no action on the recommendations and the issues.

Capacity Management is also unlikely to be one of the first processes to be implemented in a green field environment, and is often implemented as a knee jerk reaction to performance problems. If so, identify the top 1 or 2 services that have been impacted by incidents where Capacity has been potentially identified as the; or are critical to the business. For initial ease try to avoid those which have shared infrastructure, but this may not be possible. Implement a Capacity Management process on these services. Tweak. Apply to some other services. Tweak again. Repeat. Even if it's right first time round there will be priority and focus changes that mean the process will need to change.

Getting Started With Capacity Management

Before going any further, you may also be interested to read this post looking at the question - What Is ITIL Change Management?

And If You Are Not Starting From Scratch - Capacity Management – A Quick Checklist

  • Is there a Capacity plan in place? How frequently is it produced?
  • What is with scope of Capacity Management for the supplier?
  • Are performance thresholds clearly documented and understood?
  • Are work patterns monitored and how are they handled?
  • How is growth monitored?
  • How are capacity related incidents handled?
  • Are any tuning activities in place?
  • How is new technology assessed?
  • How is future demand forecasted and assessed?
  • How are performance related threshold monitored and reported against?
  • How is Capacity Management involved in service sizing and service design?
  • Does the supplier have access to strategic planning data?

Moving forward you will need to decide how your IT department connects to your company business. Understanding demand and what business actions affect your infrastructure will be critical and how can you track both. You will need to connect with the people who know the most about these business actions, because you will need to fully understand the process and how it will grow in the future. Usually at some point you will get involved in system performance so be ready for that.

As said previously if you are trying to implement Capacity Management without Service Level Management and Demand Management in place you will most certainly struggle. These two processes have major inputs into Capacity Management. If you have not defined your service levels, your customer will define the capacity levels for you and these expectations may be unrealistic, especially if they opted for lower-tier services.

A Service Catalogue and knowledge of the underpinning infrastructure components (through Service Asset and Configuration Management process) that are supporting them is essential, so when you are warning the business customers about capacity issues you can relate it to risks to their operations which help when investment is needed.

It’s also important to work on ensuring good relations and good communications with customers, to ensure that you are getting the right information at the right time about expected business changes that will change the loads on your systems. And this needs to be followed up quickly with some highly visible quick wins, so as to help build trust and confidence in IT's capabilities.

Hopefully, this has got you thinking about capacity and performance at your organisation and how it is actually managed…If at all.

Getting Started With Capacity Management

If you are considering formal training in Capacity Management it may be worth considering the intermediate level ITIL® course, Planning, Protection & Optimisation, which not only covers the activities and role of Capacity Management, but also availability, IT service continuity and IT security and their interfaces. Alternatively look at the Service Design Intermediate level ITIL® course if your role is more supervisory.

Or if you or your colleagues are new to ITIL, then the foundation training course is a great place to start.

About The Author

Steve Lawless

Steve Lawless

I've worked in IT for over forty years and spent the last twenty in training and consultancy roles. Since starting Purple Griffon in 2002 I've taught over three thousand individuals in a variety of subjects. I hold qualifications in all four versions of ITIL®, ITAM, UX, BRM, SLM, SIAM, VeriSM, and AI, and co-authored the BCS AI Foundation book. Outside of work, I enjoy skiing (or rather falling over at high speed), reading, science and technology, and spending time with my loved ones.

Tel: +44 (0)1539 736 828

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