ITIL® is a Registered Trade Mark, and a Registered Community Trade Mark of AXELOS, and is Registered in the U.S. Patent and Trademark Office This site uses Akismet to reduce spam. That asset also had two hours of unplanned downtime because of a breakdown, and eight hours of downtime for weekly PMs. See How to Calculate Reliability and Maintainability to calculate I.T. What is the availability if I add a standby system (n+1) and how shall I calculate it? Availability calculations should only be applies using the total amount contained within the Agreed Service Time. For an SLA of 99.999 percent availability (the famous five nines), the yearly service downtime … I have a questions here. Uptime is generally the most important metric for a website, online service or web based provider and is expressed as a percentage such as '99.9%'. Generally, availability is measured in terms of percentage over the expected operation time. service reliability and maintainability. You know that providing facts and data is a great way to mitigate drama and communicate growth. The most common measures that can be used in this way are MTBF and MTTR. How to Calculate I.T. The following is the formula to calculate service availability: 1 Service Availability = MTBF / (MTBF + MTTR) The above can also be used to calculate service availability of downstream services to calculate overall service availability. That asset ran for 200 hours in a single month. Literature. To obtain the necessary buy-in and confidence from the Business / Customers, the report needs to accurately reflect the availability of the relevant services provided and agreed to in the. Reliability is the probability that a system performs correctly during a specific time duration. Planned Maintenance windows / slots / periods are normally agreed with the business in advance and often captured in an Service Level Agreement and underpinned with Operational Level Agreements. If you prefer to respond without posting your comment please use our contact form. All trademarks and tradenames are gratefully acknowledged. Today data-carrying networks take a central role for many companies and high network availability is … Your email address will not be published. How many people would be required in a general shift if there are 1000 calls per day? Using your second question as an example if you are implementing or have implemented an emergency change that has effected the availaiblity of a service to its customers, if you have a 'routine maintenance' change planned around the same time you consider re-scheduling if possible to a later date with the agreement of the customer/business representative. The first is simply how you calculate the availability of a system that has been in operation for some time. When determining Availability, what impact does routine maintenance and emergency changes have on the measurement, if at all any. Availability is expressed as: (Agreed service time – Down time)/Agreed Service Time Availability Manager is the process owner of this process. Monthly availability = 100% x (730 – 8) / 730 = 98.9%. services that you rely on to operate your organization. The classification of availability is somewhat flexible and is largely based on the types of downtimes used in the computation and on the relationship with time (i.e., the span of time to which the availability refers). service. MTBF is Mean Time Between Failures MTTR is Mean Time To Repair A = MTBF / … There are two more formulas for Service Availability, this one here relates only to a single instance of a productive unit. Here is Evan's answer: There are two different ways to interpret your question. Availability for business managers and I.T. It may be true that we live in a world that ranges from 24/7 pharmacies to 24/7 fast food restaurants. Availability is the percentage of time, in a specific time interval, during which a server, cloud service, or other machine can be used for the purpose that it was originally designed and built for. It is your job as the I.T. Service Availability, I.T. But they rarely hear about positive I.T. For example, email in your organization will probably need to be available 24 hours a day/7 days a week. The main goal of the Availability Management process is ensuring that the level of service availability meets or exceeds the current and the future agreed needs of the businessin a cost efficient way for all delivered services. AVAILABILITY MANAGEMENT (FACTS & FICTION), How to Calculate Reliability and Maintainability, IT Availability Management, (Facts & Fiction), How to Calculate Service Reliability and Maintainability, Additional Availability Definitions and Informations, I.T. The second formula provides a means of calculating the availability of a specific group, region or … If you’re looking to benchmark your operation against the best in the world, top-tier organizations achieve system availability of 90% or higher. You will need to provide and verify your e-mail address but your personal information will not be published or passed on to others. ISO® is a Registered Trade Mark of the International Organisation for Standardisation. Those of you who are familiar with I.T. Therefore, as part of a monthly performance report to senior management you provide an availability report that highlights the availability of key I.T. I.T. It states the guaranteed level of availability. For instance, if an IT service is purchased at a 90 percent service level agreement for its availability, the yearly service downtime could be as much as 876 hours. professionals alike. This report may show that availability has improved as a result of a capital investment in technology resources. Thank you for your question and hopefully we have understood it correctly. In addition with my ITIL best practice hat on I would also expect or encourage that even rountine maintenance outages follow the Change management process to enable the 'Change' to be assessed against all other changes taking place and also in relation to the demands of your user or customer base at that time. The formula most commonly used to calculate uptime is the following: Availability (%) = Uptime/Total Time Where Total Time = Downtime + Uptime With this formula we can derive the maximum amount of downtime that a service can suffer in order to meet its Service Level Agreements (SLA): Ideally, most enterprises (and cl… As a result, there are a number of different classifications of availability, including: 1. News & Views, Tech Tips (Small Churches) With this in mind here are a couple practical applications for measuring I.T. It digs a little more deeply into the topic of I.T. Inherent Availability 5. This translates into an availability of 90% but a reliability of less than 1 hour. Understanding RMON for Monitoring Service Quality, Understanding Measurement Points, Key Performance Indicators, and Baseline Values, Defining and Measuring Network Availability, Measuring Health, Measuring Performance 100. managers. maintenance)? Service Availability (ITILv3) To measure the availability of a service, you can subtract the amount of downtime from the Agreed Service Time (AST), then divide the result by the AST. If the web host doesn’t deliver that uptime level, you will be entitled to refunds or hosting credits. Inherent availability (Ai) = 713940 / (713940+1) = 713940 / 713941 = 99.999860% Inherent unavailability = 1 / 713940 = 0.000140%. With this in mind, it is important to have and communicate Agreed Service Times that outline when users/customers can expect a service to be “fit for use” and available to perform their functions as expected. As a business or I.T. They really only care about how good their “playing” sounds. For instance, if the operation time of a service is from eight am in the morning to six pm in the evening, it is active for ten hour… The mathematical formula for Availability is as follows: Percentage of availability = (total elapsed time – sum of downtime)/total elapsed time. manager should never take for granted or assume that senior management is clear about the availability of a service. Available definition, suitable or ready for use; of use or service; at hand: I used whatever tools were available. Tags; ITIL, Availability formula, Service Level Agreements, SLA, Service Level Management, Service Catalogue. They may hear complaints about a service failure. As I.T. The formulas below offer one approach to establishing the availability of a service and depending on the level of detail contained within the Service Catalogue, together with the information collected when an Incident occurs (Incident Management), the second formula provides the opportunity to determine the availability of a Customer / Business group, region or location: The above formula provides a means whereby the availability of a service can be calculated for a specified period. NB: We respond personally to every post, if it calls for it. I know…I just wrote about I.T. How To Calculate Acceptable Downtime From a Known Availability Percentage The above formula provides a means whereby the availability of a service can be calculated for a specified period. Formed in 2001, it promotes development and deployment of commercial off-the-shelf (COTS) technology. The first is simply how you calculate the availability of a system that has been in operation for some time. However, technology still burns resources and costs money to operate. How to Calculate I.T. manager you are looking at the Service Level Agreement from a Software as a Service company that specializes in Sales support. 0. Scope & Process). Weekly availability = 100% x (168 – 8) / 168 = 95.2%. Please submit any comments you have about this article. In the money collection example, the availability is calculated for all end-user applications (websites, voice recognition, etc. To identify each post we take the part of your email address before the @ sign and use that as the identifier, so if you are john.smith@itilnews.com your post will be marked "by john.smith". pixabay for various (free) images, var mailme0 = "mailto:";var mailme3="edit";var mailme1="or\@itilne";var mailme2="ws.com";document.write(""+ mailme3 + mailme1 + mailme2 +"<\/a>");[please use the contact form], by post c/o Through the Line LimitedGillingham, DorsetSP8 5ET. management is about adding value and that sometimes I.T. The second formula provides a means of calculating the availability of a specific group, region or location, where the service is delivered. Quarterly availability = 100% x (2190 – 8) / 2190 = 99.6%. availability management strategies. For that, I offer the simple formula: NB: This page is © Copyright ITILnews.com and / or the relevant publishing author. Furthermore, I.T. services don’t actually need to be available 24 hours a day 7 days a week. 1.3 Availability has various meanings and ways of being computed depending upon its use. The reality is that many I.T. For example, few people really care about what techniques a professional guitar player uses in a performance. In other words, reliability of a system will be high at its initial state of operation and gradually reduce to its lowest magnitude over time. Availability, by definition, is expressed as the percentage of actual operation time that the equipment is used out of the total time being observed. Featured, News & Views, Righteousness & Justice, Faith, Featured, News & Views, Righteousness & Justice, Your email address will not be published. Uptime Guarantees Inventory availability checking is the calculation of the quantity of the part that is available and can be reserved for a customer order. They really only care about the value that you add to their lives through technology. However, payroll may only need to be available 10 hours a day 5 days a week. Required fields are marked *. A piece of equipment can be available but not reliable. Many people defer to 24 hours/7 days a week as an agreed service time by default. As an I.T. Shift timings are from 9am to 6pm and average handling time is 15 minutes. accomplishments. See more. Outage due to equipment in hours per year = 1/rate = 1/MTTF = 0.01235 hours per year. Thanks to; managers get too caught up in process and lose sight of value. I.T. services. Service Maintainability. ITILnews and its contents are not associated with nor endorsed by AXELOS. In the form of an equation, availability is expressed as: Availability (%) = [Actual operation time (hours)/Total time (hours)] * 100 Where the actual operation time can be obtained by deducting any planned or unplanned downtime from the total time: Actual operation time = Total time (hours) – Total downtime (hours) For example, say a working mechanical mixer is obs… System availability is calculated by dividing uptime by the total sum of uptime and downtime.Availability = Uptime ÷ (Uptime + downtime)For example, let’s say you’re trying to calculate the availability of a critical production asset. availability so why am I writing yet another post on the subject? Candidly computer users and customers that you support don’t care about best practices in I.T. With all of these details, you might be asking why this is so important? In the traditional IT availability calculation, service level agreements (SLAs) are set for application uptime, and application availability is calculated against those SLAs. service availability alone doesn’t necessary offer a complete measure of I.T. How do you consider the planned downtime (i.e. During this correct operation, no repair is required or performed, and the system adequately follows the defined performance specifications. Wrong. This article has been viewed 64193 times. For instance, if the shift length is 10 hours, and the service/repair time per shift averages one hour, the total availability of that piece of machinery is 9 hours, or 90 percent. Steady State Availability 4. Click the REVIEW button below to preview your comments. E&OE. If we let A represent availability, then the simplest formula for availability is: A = Uptime/(Uptime + Downtime) Of course, it's more interesting when you start looking at the things that influence uptime and downtime. Achieved Availability 6. leader to communicate in measurable and objectives ways that the technology you steward is a good investment of organizational resources. Subtract the total service/repair hours of Step 3 from the total availability hours of Step 2. Agreed Hours - (Incident (s) x Duration) x. availability: 1) In a telephone circuit , availability is the ratio between the time during which the circuit is operational and elapsed time. Or, perhaps you want to communicate on a Quarterly basis that your technology infrastructure/staff is maintaining availability as a key contributor to the productivity and continuity of your organizational initiatives. Instantaneous (or Point) Availability 2. It doesn’t have to be this way. Technology still requires good leadership and even in this time of the perceived continuous availability that we observe in our cloud service world, technology fails. There is 1 comment awaiting user validation. availability. I mention this in conclusion of this post in order to acknowledge that excellent I.T. Average Uptime Availability (or Mean Availability) 3. Therefore, the availability calculation looks like this: Availability = 100 ÷ (100 + 10) Availability = 100 ÷ 110 Availability = 0.909 Availability = 90.9%. In any case an I.T. Calculate how much downtime should be permitted in your Service Level Agreement or Objective. Ability of a Configuration Item (CI) or IT Service to perform its agreed Function when required. PRINCE®, PRINCE2®, M_o_R®, P3O®, MSP®, P3M3®, MoV®, MoP®, PRINCE2 Agile®, RESILIA™, The Swirl logo™, are all registered trade marks of AXELOS Limited. They claim that they agree to warranty the availability of their service 99.9% of the time to be measured over a thirty day billing cycle. vs Users – Part 2 (Value & Trust vs. Each of these is a valid figure for the availability of the service, but only one of them shows that the target was met. However, it may cost more to warrantee such availability than it is worth. To calculate the accepted downtime from a known availability percentage, Multiply the numeric value of the percentage by the AST and divide it by 100. If you have different formulas or approaches to determining the availability of your services why not share them with ITILnews.com and its community. You can then multiply the number by 100 to obtain the percentage. After-all in the cloud world nothing ever really goes down anyway right? For example - 10 users who work on same application and all are affected at the same time, it's quite possible that they raise only 1 incident but that would be for 10 users, however in a case if each one would have called up seprately, it would have resulted into 10 incidents. * Failure Rate (λ), which is defined as: number of failures / total time in service. Management standards know that measuring I.T. But in both scenarios the issue and the impact remains the same. Documentation > MAC-PAC Reference Library > Distribution > Order Processing > Key Concepts and Procedures > Inventory Reservation > Inventory Availability Checking Inventory Availability Checking . The content of this site may be unmoderated submissions from unauthenticated users and as such it cannot and does not represent the views of ITILnews.com, its Principals or sponsors. You may copy this article only in it's entirety, including any author bio and / or credits, and you must link back to. Service. Uptime is the amount of time that a service is available and operational. services. Barlow and Proschan [1975] define availability of a repairable system as … It also ensures new or changed service meet availability goals and doesn’t affect the existing services. AVAILABILITY MANAGEMENT (FACTS & FICTION) shared some high level perspectives about I.T. Notify me of follow-up comments by email. manager/professional you know that there can be a great deal of drama surrounding the availability of key I.T. Availability is well established in the literature of stochastic modeling and optimal maintenance. Why do we need the count of incidents to calculate the availibility? Providing 'routine maintanence has been specified and agreed in your Service Level Agreement and agreed together with agreed notification period then such outages should be excluded from the Availability measurement. service reliability and maintainability of an I.T. You can then subtract the result from the AST. As a business or I.T. managers can get too caught up on using Availability management as a way to create barriers for users. In answer to your questions. "In general, for any software service or system you can think of, 100% is not the right reliability target because no user can tell the difference between a system being 100% available and, let's say, 99.999% available." Agreed Hours. For example a 99.9% uptime equates to 43 minutes and 50 seconds of downtime. A quick note about Agreed Service Time (AST). Availability Management (AM) ensures that IT services meet agreed availability goals. After the tutorial I also provide some practical application for the formula in order to help you gain value from the information. To calculate the reliability of a service in MTBSI, you can divide the available time in hours by the number of breaks in service availability. Your feedback will help add value to the content for other ITILnews.com visitors and help us develop the content for the benefit of all. My recent post on this topic entitled  I.T. Reliability follows an exponential failure law, which means that it reduces as the time duration considered for reliability calculations elapses. It is important to remember the accuracy is dependant upon the Incident being reported to IT in the first place and secondly the data captured whilst recording the Incident: Hopefully the above formulas assist you with constructing your Service Level Agreements. Mike Gold ). 1. :-). If in one-year time interval, the Internet connection never failed, while the VPN tunnel was unavailable for 1 day, then the value of the overall network availability for that location is: Network Availability = 80% * 100% + 20% * (99.726%) = 99.945% manager, it is important to take a candid look at different I.T. So why am I writing yet another post on the subject Incident ( )! Complete measure of I.T writing yet another post on the measurement, if it calls it! 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