Prject Management review - Essay Example

Download file to see previous pages The two major categories of estimation are ‘Macro or Top-down approach and Micro or Bottom-up approach’ (Sihombing).
The Macro or Top-Down approach
This approach is used to make a quick and rough estimation of project cost and time, when the time and expense of a detailed estimate are some issues. Often macro approach is carried out during the conception stage as there is no full design or Work Breakdown Structure available. The macro approaches may have high chances of inaccuracy and therefore, only well experienced personnel can do the estimation. With the help of a similar previous project, the estimation becomes easier. As Gray and Larson (2008, p. 134) point out, the expenses for the foremost subunits of the new project would be proportional to foremost subunits in the previous project.
The Micro or Bottom-UP approach
The Micro approach takes the project design and a ‘roll-up’ of Work Breakdown Structure elements into consideration (Project management). As it is a detailed approach, it requires multiple personnel and much time to complete the process. If the bottom-up estimate is done properly, it can yield accurate cost and time estimates. The costs for the higher level units are obtained by rolling-up the estimated time and cost connected with the lowest level Work Breakdown Structure packages. And this approach renders the most accurate estimation within the time devoted to developing the estimate. Factors affecting the estimation of Cost and Time There are several significant factors that affect the estimation of project cost and time. The most important factors are; Task Definition: The comprehensiveness of the definition of the project helps to determine whether all tasks have been taken into account. Project Structure: The structure compacted with a dedicated project team will always focuses on the effective completion of the project. Padding: there are chances of increasing the estimates in order to consider the unknown risks which in turn may cause an unwanted trade-off. Culture: It refers to the acceptable behavior of the organization which influences the estimation. Downtime: It is the lapse of time which affects the time estimate due to equipment repairs, holidays, vacations, etc. II An Ideal Approach According to Rosenau and Githens (2006, p. 133), planning, estimating, and resourcing are the most important elements of a successful project; and these elements may seem to be separate issues, but required to be conducted in parallel as they directly influence each other. Estimation of time and cost is needed per each type of resources for every part of the work to be done. An ideal approach from the part of the project manager would be to hold all the different elements and criteria together in a multi-dimensional model. The project manager should make sure that the estimation is done by a person who is most familiar with the task. And if possible, it is better to collect estimates from several people and find the variation of risk assessment. In order to avoid the ‘group think’, multiple estimates must be conducted independently. The project manager should use consistent units while estimating task time and the estimates should be based on normal conditions. The ...Download file to see next pagesRead More