Indeed, a mock-up or visual of some sort is essential. The result. Items are estimated into t-shirt sizes: XS, S, M, L, XL. Jan 28, 2015 2 What is ‘Magic Estimation’ about? It’s an exercise for the Scrum team to estimate an entire product backlog with. Estimate complexity or effort with your scrum team on a collaborative real-time board using a turn-based Magic Estimation game, consensus-based Planning Poker or Async. Flow. An estimate is our best guess for what can be achieved and by when. Jeder User Story soll die passende Anzahl an Story Points zugeordnet werden. Scrum is designed to be applied in complex environments within which people address complex adaptive problems. Effort Estimation at the Backlog Item Level. Inadequate early scope estimation is a common problem in software projects, leading to failures in meeting project requirements. It’s a useful format to get some insights of the size of a backlog. Gain skills you can apply immediately via “9 practical exercises”. Estimating is about creating a shared understanding of the requirements, and a shared understanding of the. Several methods exist to estimate Story Points, including Planning Poker and Magic Estimation. If you believe. Estimation helps the Product Owners decide if something’s worth doing. Take the top card from this pile and place it on the. You may have heard about them under various names: Silent Grouping , Magic Estimation , Affinity Estimation. Estimation Techniques. Introduction Effective project estimation is crucial for successful project management. This rate is calculated by the difference between previous estimation "magic" with the real estimation "planning poker". # 4) Nachfolgend sind einige häufig gestellte Fragen unter den Teilnehmern aufgeführt:. Improve team's estimates in Story Points, hours, or use any custom Jira numeric field. Follow. " Tools like Planning Poker or Magic Estimation are then introduced to fill the gap, and "Story Points" are offered as an alternative. Scrum). In other words, you evaluate how much work you can fit into Sprints and where that leaves you. In Phase 1 of the game, Team Members order all stories in the the batch from Lowest Complexity to Highest Complexity. March 23, 2020. Dies wird meistens vom Scrum Master durchgeführt. Agile Forecasting Techniques for the Next Decade. Suz Maria. Das Refinement Meeting war früher das. Top-Down Estimate. Being an Agile Coach & Trainer for Prowareness, I use different types of games, tools and practices every week during meetings, workshops and trainings. “Scrum Guide doesn’t prescribe to use any estimation technique, like Poker planning, magic estimation, story points, focus factor, dirty hours, T-shirt and persondays. Determine the Impact I (1=low, 5=high). Posted on December 26, 2017 January 4, 2018 by Zoltan Weber. Learn about Planning Poker and T-Shirt Sizing estimation methods. Most teams estimate their work with story points. Total: [Sprint 2] + [Sprint 3] + [Sprint 4] = 180. Story points are not a Scrum concept. Use story point estimation to make more accurate projections. T-shirt sizing. Myth: Story Points are Required in Scrum. Whenever a user story you estimated and cannot be completed in a single sprint, you should call it an “Epic” instead. Estimation. Estimation is essential in Scrum to optimize resource allocation and monitor progress, allowing the team to allocate resources to tasks that require more attention. The Developers do the estimation. It is the main source of input for estimation and planning in Scrum. Divide the Product Backlog Items between the workshop participants. Magic Estimation is a rapid estimation technique especially valuable for quickly estimating a large set of product backlog items. An estimate seeks to determine the effort or cost of a project or task. It enables us to gain a clear idea of what can be realistically achieved and when. The majority of the teams that we work with do this, and there really is nothing inherently wrong with it. What are estimation techniques in scrum? Estimation techniques in scrum is considered as the User Stories for the sprint by priority and by the ability of the team to deliver during the time limit of the sprint. Magic Estimations - Async and Planning Poker sizing for Jira. View Magic estimation PowerPoint PPT Presentations on SlideServe. The team decides to deliver the first 1,000 fields in the first Sprint and the second 1,000 fields in the next, and so on. So kann der Product Owner seine Product Backlog Items verfeinern. – Dropped balls do not count. Animal Sizing suggestions. Use: Prioritization of user requirements This is a method described in the book "The Ultimate Scrum Guide 2. November 2022 by RolandWanner. In its case, it’s much wiser to follow an interactive approach and review software development estimates at each sprint. Team Estimation Game has an opinion of the most effective estimation technique for most Scrum Teams. 0". The purpose of estimation in Scrum. Scrum Teams bedienen sich relativer Größen, da Menschen Relationen leichter bestimmen können. In the previous case, B could be a 3 or 5 and there's a clearer idea of. Planning poker, T-shirts, Bucket System, Large/Small method, Dot Voting are the top five best scrum estimation techniques to estimate your team’s work efficiency. As a Scrum Master, choose issues from previous sprints as reference points. Magic estimation, a technique for fast estimation of multiple items. Introduction. This way, teams can better understand the estimation process and easily break epics into smaller ones. Agile Manifesto focuses businesses on delivering value in the form of working products, building in close collaboration with customers to react (or even initiate) to changes. The team decides to deliver the first 1,000 fields in the first Sprint and the second 1,000 fields in the next, and so on. Scrum says that this is a cross-functional group "with all the skills as a team necessary to create a product Increment". About me; Subscribe to RSS; June 2, 2014 in estimate; 1 Comment;. The method's. It's a relative Estimation Technique. At the beginning the Product Owner presents a ticket that needs an estimation. That’s why more and more Scrum Teams are using *Magic Estimation”, a method Boris Gloger adopted and refined from. For example, say you’re planning the development phase for your product. Category: General Scrum myths Danger: High The basis of the myth One of the first things we learn in most Scrum trainings is: "We don't want to plan in Man-days, because that doesn't work out anyways. I started with a little game (this to fresh up the brain). If the user stories are very vague or complex, you may need to use a larger. Gain in-depth knowledge of the most popular estimation techniques used by modern agile teams. Traditionally a plan that does not complete is often seen as a call for more planning and improved estimation. It was first published in 1792 by Robert B. Ideal time is not a Scrum concept. Estimation based on practical inspection is the way to go. Estimates aren't for use by stakeholders outside of the team. Gain skills you can apply immediately via “9 practical exercises”. And. Sprint 3: 5 user stories x 12 story points = 60. This is where "Scrum Magic"comes to the rescue. The question itself doesn’t bug me, but the misunderstandings of estimations do. Tshirt sizing is a popular scrum poker alternative. How to Estimate the Effort of Backlog Items With Points Using Planning Poker and Magic Estimation. Sprint Poker: Minimize bias and boost precision 🃏. This game allows a team to quickly review 5-15 items, organize them in relative rank order, and then assign a value scale to those items. The product backlog should be prioritized, refined, and updated regularly to reflect the changing needs and expectations of the. g. => Laden Sie hier das Agile Poker Tool herunter . You can use it to estimate the work required to redecorate your home, landscape your yard, organize an office move — the list of potential applications for planning poker is endless. Scrum Magic: Ultimate Training Guide to the Agile Framework is a revolutionary master class about the Scrum framework. Using this technique you get a quick feel on the perceived effort of the. But no one glimpsed into this. Der Scrum Guide hält diese unmissverständlich fest: „Der Product Owner ist verantwortlich, die Reihenfolge der Product-Backlog-Einträge festzulegen. The team calculates that the 500 hours would take 2. Wall estimation - Assigning numeric values by collaboratively placing and moving cards on a wall, also referred to as magic estimation or silent estimation. Team estimation game play. All of these things are used by some people as part of their work with Scrum. – You cannot pass a ball to someone directly to your left/right. ) A. For example, the arrangement goes like 0-1-1-2-3-5-8-13 and moving on. Outil recommandé # 1) Poker agile. What is 'Magic Estimation' about? It's an exercise for the Scrum team to estimate an entire product backlog with story points in a reasonable short amount of time. Scrum Masters are open-minded and communicative people. 1. People from all over the world often ask me this question. Let the Product Owner select the best. Dot Voting. After 4-5 rounds of estimation , the answer is still the same. Herramienta recomendada # 1) Póquer ágil. Magic Estimation bietet sich vor allem an, wenn ein Team ein regelmäßiges und häufiges Product Backlog Refinement durchführt, dafür nur wenig Zeit aufwenden kann oder viele Stories auf einmal schätzen muss. Today we address the idea that work on the Product Backlog must be estimated in Story Points. PO does it to maintain the backlog and to generate work for the next sprints. Trainings & Workshops für agiles Arbeiten, Scrum Master und Product Owner Zertifizierung. See it in action: 3-minute overview video The general concept behind the app is Magic Estimation method (also referred to as Silent Grouping, Affinity Estimation, Relative Estimation, Swimlanes Sizing). But nevertheless they give us a valuable guideline and basis to do a conversation. Magic Estimation mit Backlog Items Als nächstes wird dieses relative Sortieren mit 15 bis 30 Backlog Items wiederholt. It's a useful format to get some. This paper presents the methodology for. Recognize when to re-estimate & when not to. Many teams use T-shirt sizes (S, M, L, XL), but you can also use the Fibonacci sequence (1, 2, 3, 5, 8, 13, 21, and so on). Scrum is an agile project management framework that helps teams structure and manage their work through a set of values, principles, and practices. In plan-based approaches, estimates are used to arrive at. October 2022 1. You can use different methods. Existing teams propose how they would like to go about organizing into the new structure. No. And have the Product Owner print each product backlog item on a separate sheet. In this blog post, I will describe a method and my experience with it as a Scrum Master. Flow metrics or counting items Magic Estimation Game is a relative estimation method, also known as ‘silent grouping’ or ‘affinity estimating’. The Agile planning practices discussed in this course will assist managers improve their planning process and correspondingly, improve the decisions they take. Calculating team velocity and planning project schedule . Optional facilitation by a Scrum Master or Product Owner. Using these benchmarks allowed us to estimate the whole PBL with magic estimation. As a scrum master how do we solve this. Align priorities. It is much easier to say that an elephant is bigger than a gorilla than to measure both animals’ height or weight. As a result, the team failed to deliver all of the features in the sprint backlog for the past two iterations. By estimating it. It is used e. Bug Estimation in Scrum. It is one of the primary steps in Agile Scrum. Estimation units: This is a unit of measurement for relative sizing techniques. There are some T-Shirt sizing cards out there, but on these cards are also numbers displayed. Honorable mention: Estimate extension allows the development team to do Planning Poker estimation with selected items and immediate. The total ideal hours = 10*9*7 = 630 total hours of work for a 2-week Sprint. The paper proposes an estimation method for the Product. 2. In our Scrum Teams, we spend 1 hour on refinement per Sprint of 2 weeks. Time is used for sprint review, retro, and planning. . “What is ‘Magic Estimation’ about? It’s an exercise for the Scrum team to estimate an entire product backlog with story points in a reasonable short amount of time. Their responsibility is to keep healthy communication, as it is an effective force, which holds the team together. Scrum simply states that items should be estimated, however how to estimate is left blank. . Sizing is typically done in a Refinement meeting. You get better at estimating by analyzing what information you uncovered after the estimate that would have changed your original estimate. It is proposed as either an alternative approach or preliminary to "Planning Poker", a technique common to agile project estimation. The “poker” aspect of the name refers to the cards that. The most commonly used Agile estimation method, Planning Poker helps minimize the likelihood that participants will influence one another, which increases the accuracy of the final estimation. The general. Complementary Practices to Scrum. 3. Next, every team member had to take one number, read all of the stories assigned to this number and check the relative size against the other stories assigned to this number thus confirming the estimate. 4- Estimate Range. The third step is to adjust the estimation scale according to the level of uncertainty and risk of the user stories. Wideband Delphi. This would not include non-contributing managers (contributing managers is a whole other conversation. org does not endorse user-submitted content or the content of links to any third-party websites. Magic Estimation mit Backlog Items Als nächstes wird dieses relative Sortieren mit 15 bis 30 Backlog Items wiederholt. The selection forms the basis of the Sprint Backlog, which is a forecast of the work needed to achieve a jointly agreed Sprint Goal. But the more you do it, the better and more efficient you get at it. This is the question. Auch bei Magic Estimation wird mit Storypoints gearbeitet. 5 from 1 rating. It assumes that developers are not good at estimating how long a task will take. an Agile Logbook. A Scrum team has to decide how much work to include in a sprint. Browse . Scrum and CMMI: a magic potion Systematic was established in 1985 and employs 371 people worldwide with offices in Denmark, USA and the UK. If activities are estimated, the Product Owner is not absolutely necessary. 9 developers on a Scrum Team. A story point is a singular number that represents a combination of qualities: volume, complexity, uncertainty, and knowledge. The team calculates that the 500 hours would take 2. “Scrum Guide doesn’t prescribe to use any estimation technique, like Poker planning, magic estimation, story points, focus factor, dirty hours, T-shirt and person-days. However, not everyone is comfortable with using story points, a. During sprint planning we estimate all user stories planned for the sprint using story points. Best known technique for facilitating team estimation. Agile Scrum and generally, the agile approach to software development, has been around for 27 years at the time of writing this article. ”. These techniques help Scrum teams break down complex tasks into smaller, more manageable units, enabling accurate forecasting and. So you need to get the magic estimation and use same user story in planning poker to "calibrate" the rate. Magic Estimations is an app that helps Agile teams estimate the complexity or effort of user stories quickly and efficiently. Magic estimation. If the Product Backlog is refined too far out, it can become an example of lean waste. Idea behind Magic. The numbers have no meaning in themselves, but only in relation to other items. And explained how magic estimation works. Magic Estimations is an app that helps Agile teams estimate the complexity or effort of user stories quickly and efficiently. About the Author Kiryl Baranoshnik is an experienced Agile and Lean practitioner. Good planning is one that reliably supports managers’ decision-making. 46K subscribers. Decoupling this scenario: 1. Despite all the coaching and training, developers somehow always revert the numbers on the poker cards to time. Sometimes you may want to estimate a chunk of backlog items in a short period. The essential tool for a fast and effective estimation perfect for scrum or kanban planning sessions. Kỹ thuật Estimation trong Agile. Relative estimation is a technique used to estimate the size, complexity, and effort required for each Product Backlog item. . Beratung für agile Methoden & Lego Serious Play Workshops | HelloAgile Keywords: task board, magic estimation, scrum alliance vs scrum. (See our recent article How to create a point system for estimating in Scrum. If you’re not already there, navigate to your team-managed software project. The Team Estimation Game is most commonly used by work. Agile estimation is a crucial part of the Scrum methodology, which allows teams to predict how much work can be completed in a specific period. Upcoming Agile Management Batches & Dates. Photo by RG Visuals on Unsplash. Scrum only establishes some rules of the game around estimates and gives the teams freedom of choice on what estimation technique to use”. Planning poker, also called Scrum poker, is a consensus-based, gamified technique for estimating, mostly used for timeboxing in Agile principles. Recognize when to re-estimate & when not to. To be clear, many Scrum teams use story points for task estimation, but it is much more common to use hours as the unit of measure for tasks. Hiện nay, những mô hình quản lý dự án và mục đích chung của các mô hình này đều hướng đến việc tạo ra sản phẩm tốt, bàn giao cho khách hàng đúng deadline. Access the Estimation app from the collaboration toolbar and select Start new session. You must also mention the agile development method to be used in the contract (e. While doing so, the story was marked with a sticker and the original number was added. 4. This means that the Product Owner is responsible for the requirements, determines which requirements are implemented and in which order. Agile projects usually do not concentrate on a comprehensive requirements analysis and specification before the start of the project, making scope assessment difficult. As CEO of Mountain Goat Software, Mike’s focus is coaching, training, developing new courses, sharing ideas in his blog posts and tips, and participating in the Agile Mentors Community, especially with the live Q & A sessions. Although it’s an outgrowth of the Wideband Delphi process from the 1970s, planning poker greatly simplifies the process and is designed to be conducted with live teams having. Everyone on the team participates, with the goal of creating a product backlog that describes functionality for at least the next two to three releases. Priority Poker. – The session should take 35-40 minutes. Don't fall into the trap of equating an estimate to the hours it took. Magic Estimation and the right comparison stories. Magic Estimation. Auch bei einer ScrumEinführung ist Magic Estimation vor dem Start des allerersten Sprints nützlich, um Ordnung in eine Masse von Anforderungen zu bekommen. While we were planning the “Agile way,” we still fell into the trap of over-commitment when the new idea (points) did not line up with the old approach (hours). For example: Add a product to a drop-down menu is 1 story point. If you are searching for a perfect way to predict effort, I…5. 'it. Magic Estimations is an app that helps Scrum teams estimate the complexity or effort of user stories quickly and efficiently. Several methods. If you estimate with Magic Estimation (which I find more helpful), bugs should also be on your estimation board. It is a great alternative. Preparing the Sprint Planning: T-2: Address the number of open tickets in the “code review” & “ready for acceptance columns. They are guesses made at a point in time based upon the information you had available. In this Scrum Tapas video, Professional Scrum Trainer Dominik Maximini provides a set of analogies to help understand ways of estimating work against each other and independent of each other, the reasoning behind his thinking and tips for success. See it in action: 3-minute overview video. Fibonacci, paired with User Stories being high-level estimations, gives a more approximate idea (educated guess) of how complex a feature is going to be. If you work on or around product, engineering, or software development teams, you’ve likely. When first enabled, the Story point or Original estimate fields are. It lays out the core concepts very clearly and placed a lot of optional practices like burn-down-charts, Story Points and Magic Estimation into a broader context. In Scrum, the idea of a sprint is well named: as a team, you are trying to complete work on a. If you need to estimate 50 or 100 user stories, Planning Poker is too slow. Common point systems include Fibonacci or a simple scale from 1 to five. 5 sprints (500/40 hours per week/five team members). Procedure. Bug Estimation in Scrum. Is it one month, 3 months or 6 months of work we’re talking. Estimating the effort required for completing work items in Agile projects can be a daunting task. The people that will do the work, need to be the ones that estimate it. I have made a video where I tell about one really useful technique called "Magic Estimation"… | 62 comments on LinkedInTypically a Product Backlog item goes through three refinement meetings before it is considered to be in a ready state. SCRUM for Startups. Relative Estimation. During Sprint Planning, a Development Team will meet with the Product Owner to agree on a selection of work from the Product Backlog. Being an agile developer means to me living the agile mindset. Magic Estimations is an easy and intuitive free Jira app for quick backlog estimation inspired by a popular Magic Estimation game. Scrum Event: Refinement. Part 1: Roles and structure in Scrum. Best Agile Estimation Techniques. That’s when Magic Estimation comes in handy: depending on your speed, you can estimate up to sixty stories an hour!Magic Estimation. About Press Copyright Contact us Creators Advertise Developers Terms Privacy Policy & Safety How YouTube works Test new features NFL Sunday Ticket Press Copyright. g. A. Magic Game Estimation. However, it gets more confusing when it comes to agile ways of working since we discover requirements progressively in agile. Unlike classic project management, agile teams strive to estimate complexity because the effort differs depending on who works on it. , Which of the following activities are included in the Product Backlog refinement? (Choose multiple answers), The Scrum Master should ask each member to answer the three standard question at the Daily Scrum and forbid other. Especially when you have several concurrent scrum teams working on the same product. Who I am…. This means involving the whole Scrum team, including developers, testers. In addition to authoring. Step 1: Select point System. It describes a set of meetings, tools, and roles for efficient project delivery. One person will not be able to fulfil all his responsibilities in 100 %. Scrum only establishes some rules of the game around estimates and gives the teams freedom of choice on what estimation technique to use”. These historical issues will be benchmarks for the whole team to secure a better understanding of future estimates. D. User Stories: An Agile Introduction User stories are one of the primary development artifacts for Scrum and Extreme Programming (XP) teams. Teams are called “Squads”, and they can choose their own Agile way of working, like Scrum or Kanban. Sie reichen von 1 bis 100. Magic Estimation is a rapid estimation technique especially valuable for quickly estimating a large set of product backlog items. What is ‘Magic Estimation’ about? It’s an exercise for the Scrum team to estimate an entire product backlog with story points in a reasonable short amount of. Frank, the team’s scrum master, has cleared space on a long section of wall in the team room, and now the team assembles in front of it. Here’s how we did it. Backlog Refinement: Das gesamte Backlog in 60 Minuten verstehen mit Magic Estimation. Out of several estimation techniques involved in Scrum, few are noted below. The Scrum Mythbusters Exercise. g. Many long-time Almanac followers claim that its forecasts are. Vote unbiasedly on work items by giving estimates in complete silence. Multiply the Impact (I) by the Probability (P) to obtain the R isk Value R=IxP. I’m a software craftsman living in Germany, coding computer programs since I was 16 years old. Subscribe. And have the Product Owner print each product backlog item on a separate sheet. The goal of the study is to develop a method of intermediate estimation of software development project duration supposed to be implemented by Scrum teams. The first Scrum Guide, published in 2010, discussed estimation left, right, and centre. The cards with the user stories. What Scrum Says About Estimates. With that established let’s take a look at Magic Estimation, originally introduced by Boris Gloger on the South African Scrum Gathering. For teams that are using scrum with Azure DevOps service/server marketplace extensions are powerful additions the tool coverage of scrum framework and will simplify adoption of scrum withing a development team. The only important opinion is that of the team. People from all over the world often ask me this question. . More complex stories might be broken down into more tasks than simpler stories. For example, let’s calculate sprint velocity based on the below data: Sprint 2: 4 user stories x 12 story points = 48. Scrum only establishes some rules of the game around estimates and gives the teams freedom of choice on what estimation technique to use”. It is a great alternative. Nobody knows the exact size of a small sized t-shirt but everybody. This article explains why it is not a good practice to use story points as an estimation tool with planning poker. Relative Estimation. Cost of. Magic Estimation enables Scrum Teams to estimate a Product Backlog in such a short time that it seems like magic. One response to “Magic Estimation” Pete says : March 3, 2015 at 7:16 am. Scrum is one of the most popular agile methodologies for software development, but it requires effective estimation and planning to deliver value to customers and stakeholders. Some of these I've invented myself, but most already existed and have only been changed slightly to a format that suits me best. Myth: Story Points are Required in Scrum. Certified ScrumMaster® certification exam training in Victoria, BC from iCert Global. This technique is perfect for distributed teams. A very fast way to do this is by 't-shirt sizing'. The team then clarifies all questions regarding the ticket. It’s fast and easy to use. Das gibt dem Team für die Durchführung der Magic Estimation eine nützliche Orientierung. The fact that a small team might estimate in such a way that they have a velocity of 50, while a larger team estimates so as to have a velocity of 12, is of no concern to anyone. Let the Product Owner select the best. When it comes to estimating and Scrum, there is no official stance on what a Scrum team should do for story point estimates. You will determine the impact and probability of the risks efficiently and without long discussions if each team. 3 developers rate the user story 3,5,8 respectively. Be able to identify and troubleshoot common estimation problems. This is a perfect technique for estimating a large backlog of relatively large items. Démarrer avec Agile Poker est simple et facile car il a été inspiré par trois méthodologies d'estimation standard de l'industrie: Planning Poker®, Wideband Delphi. Display mode SCRUM FEST. But, there is such a thing as too much of a good thing. Auch bei Magic Estimation wird mit Storypoints gearbeitet. Product Owner and Scrum Master are two separate roles and mixing them can have a very negative effect on the development process. How to run a wall session. die Komplexität von Backlog-Items zu schätzen. Story point estimation is the process of assigning story points to a product backlog item or a user story. Name. Divide the Product Backlog Items between the workshop participants. Suppose you have fifty things you want to get estimated; opting for Planning Poker may take you at least four hours. Swimlanes sizing. Teams see the √π come into play when they are estimating total plannable hours in a sprint. Moreover, when Agile is adopted by organizations or when used. Plan upcoming work, Slice the stories and work smaller. Other sources provide patterns, processes, and insights that complement the Scrum framework. Teams can estimate how high of a priority their tasks are by. In this post, Merle Heidel and Tobias Maasland from inovex will discuss, in detail, the reasons why. Multi-field estimation with the optional final score. g. The following steps are required: The following steps are required: The numbers 1,2,3,5,8,13,21,? of the Fibonacci series up to 21, supplemented by a question mark, form possible size values. Estimation and. The three-point estimation method takes an average of three figures to determine the amount of work needed for an individual task: This technique is often paired with the bottom-up method to create even more accurate estimates. Thomas who wanted an almanac “to be useful with a pleasant degree of humor. 3- Affinity Estimation. Estimates, if the team chooses to use them, are best used by the team in order to plan their Sprint. The value of the separate work items for the product. That’s all there is to it. The smallest tasks are estimated at 1 point and then other tasks are weighed and estimated in accordance with that task. 2. I am in a Scrum Team and we are working with Azure Devops for our Taskboard and Backlog. Magic Estimation is an estimation technique that is quick. The purpose of backlog grooming is: Filter the backlog to ensure it has relevant items. Eine bewährte Methode, um eine große Anzahl von Einträgen des Product Backlogs zu schätzen, stellt die Magic Estimation dar. die Komplexität von Backlog-Items zu schätzen. It is especially useful to quickly estimate a large number of items. Magic Estimation - by Barry Overeem. Planning Poker or Fibonacci sequence.