Top-down vs bottom-up estimations
Contents |
Abstract
When starting a new project, an important task for the project manager, is the estimation process. This can both be an estimation regarding cost and time-frames. It is important to get the project off to a good start, given that success of the project depends on the estimation - both in regards to time and cost. When estimating (or in other words 'predicting the future'), the project manager can use the following methods:
- - Top-down approach
- - Bottom-up approach
By choosing the top-down approach, the project manager chooses to make an overall scope of the project. From here, the major elements of the project is being listed and estimated separately. This approach creates a rough idea of the project size and the different timeframes of the project elements. The advantages of using the top-down approach is less time consuming and requires a limited amount effort. The estimates created by this method often turns out larger than the ones, which has been found using the bottom-up approach. [1]
The bottom-up approach is on the other hand a very time-consuming and costly method, but it gives a more accurate estimate of the project time and cost. By using the bottom-up approach, the cost and time frame is being calculated for every activity related to the project. The values and time frames are then aggregated in order to estimate the total cost and project time. [2] The bottom-up approach is often used in order to gain stakeholders to buy in on the project.
Big idea - describe the tool, concept or theory and explain its purpose. The section should reflect the current state of the art on the topic
The term 'estimating' in terms of project management is defined as the process of predicting the cost and time needed to deliver project products[3] . The estimation part is an important step on the way to a get a good product, which satisfies the costumer and/or the user, when it is delivered in the end. The estimation proces is used in order to predict the cost and the duration of a given project, which is making it possible to make the decisions, which will benefit the project. When estimating, it is also possible to make a decision regarding the viability of the project, when the financial requirements has been determined.
The duration of a project is important to know in regards to costumer expectations and in order to know when the product can be delivered. From the estimation process, the project manager can use the determined time frames for time scheduling, which is relevant informations for interested stakeholders. During the project, the project manager can hold the real time data up against the estimated values in order to monitor the performance of the project. Cite error: Invalid <ref> tag;
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Project estimations can be a fast task, but it can also be very time consuming. This all comes down to how the project manager wishes to prioritize the estimation, and is a decision on whether the time used on estimating is worth the effort in the end. The estimation process can be carried out by using the following two methods:
- - Top-down approach
- - Bottom-up approach
Top-down approach
The top-down approach defines the way making the estimating based on genereal information about the project.
Application
provide guidance on how to use the tool, concept or theory and when it is applicable
Limitations
critically reflect on the tool/concept/theory and its application context. What can it do, what can it not do? Under what circumstances should it be used, and when not? How does it compare to the “status quo” of the standards – is it part of it, or does it extent them? Discuss your article in the context of key readings / resources provided in class. Substantiate your claims with literature
Annotated Bibliography
Provide key references (3-10), where a reader can find additional information on the subject. The article MUST make appropriate references to the and reference material provided in class – either incorporating it as a source, or critically discussing aspects that are missing from it but covered by this article. Summarize and outline the relevance of each reference to the topic (around 100 words per reference). The bibliography is not counted in the suggested 3000 word target length of the article.
References
- ↑ https://www.apm.org.uk/blog/three-ways-to-approach-cost-estimation/
- ↑ "Project Management: A guide to the Project Management Body of Knowledge (PMBOK guide), 6th Edition (2017)"
- ↑ https://study.com/academy/lesson/top-down-bottom-up-estimating-techniques-in-project-management.html
