IT Management





Guesstimatingis an approximation that is based on a mixture of broad assumptionsand computations. Top-down estimating is a high level work effortestimate that is derived by taking the total estimate of the projectand dividing it among the tasks and the phases of the project.Bottom-up estimating produces a clear estimate of a specific amountof work where each task is divided into further factors, and then theseparate estimates are advanced to determine the needs required tomeet the smaller factors of the work (Mulcahy&amp Diethelm, 2011).The pros of bottom-up estimating are: manual processes are easilyreplaceable with automation, a password management can be implementedfor a large number of users, it is not a must for the development ofcustom adapters in the early phases, and the organization is able tobroaden its identity management skills and understanding during thefirst phase.

Thecons include: the established organizational structure could need achange in a later roll-out phase, and the strategy is mainly drivenby the infrastructure that is already in existence and not by thebusiness processes. The pros of top-down estimating are: the firstimplementation becomes a showcase of the identity managementsolution, the operation and maintenance resources are impacted in aneasy way, on the completion of the phases for the managed applicationa deeper management solution gets implemented and the organizationrealizes a focused use of resources from the individual managedapplication. The cons include: only a minimal percentage of useraccounts are managed in the first phases, custom adapters aredeveloped at an early stage, the solution provides limited coverageduring the first phases, and the cost of implementation is higher.


Bottom-upestimating is the breaking down of tasks into smaller componentswhere separate estimates are advanced to determine the needs requiredto meet the work components. The work breakdown structure (WBS) isthe key project deliverable that organizes the work of the team intomanageable sections. The WBS helps in setting up a successfulbottom-up estimate exercise as all the phases and activities of theproject are defined (Marchewka, 2009). The project management body ofknowledge (PMBOK) defines the work breakdown structure and statesthat bottom-up estimating is a method that estimates the projectduration of cost by aggregation of the estimates of the lower-levelcomponents of the WBS.


TheWBS is an important management tool that lays down the work fordefining work packages, provides a basic framework for a number ofactivities such as the estimation of costs, the development ofschedules, the identification of resources, determining where risksmay occur and the provision for measuring program status using EVM. Iwould inspire a project manager who finds no real value in using WBSby giving him the benefits of this tool which are: the project budgetcan be allocated to the top levels of the WBS and so departmentalbudgets can be calculated fast based on the WBS of each project (WorkBreakdown Structure, 2009). A lot of time is saved once time and costestimates are allocated to specific sections of the WBS which resultsto the project schedule and budget being developed quickly. As theproject executes, specific sections of the WBS can easily be trackedso as to identify the performance of the project cost and theidentification of issues in the organization of the project.


WBSallows one to break down an overwhelming project into pieces that aremanageable and controllable. The creation of a WBS is a top-downeffort to decompose the deliverables and the work required to producethem into smaller work packages inclusive of the product scope, theproject scope and the project management efforts (Mulcahy, 2009).

AWBS should include the work that needs to be done and not the workitself and this statement means that when creating a WBS for aproject, there should be the culmination of multiple inputs andperspectives for the project work that needs to be done. Stating thework itself is not as necessary as every team member has their partto play in the project, and therefore it is not as important to knowwhat part another team member will be playing.


Mulcahy,R., &ampDiethelm, L. (2011). Ritamulcahy`spmp exam prep.(7thed.). Minnetonka, MN: RMC Publications, Inc. Retrieved from

WorkBreakdown Structure. (2009). GAOReports,65.

Marchewka,J. (2009). Informationtechnology project management.(3rd ed.). Hoboken, NJ: John Wiley &amp Sons, Inc.

(2013).Aguide to the project management body of knowledge (pmbok guide.(5th ed.). Newtown Square, PA: Project Management Institute, Inc.Retrieved from