Bottom-Up Estimating

This estimation technique is used to aggregate the duration or cost from the lower level of the WBS structure. Individual activities aggregated to work packages. If it is difficult to estimate at activity level then further the activity is decomposed to more detail. And estimation is done at these detail level and aggregated to activity level.

Bottom-Up Estimating is the most accurate estimation technique but is time consuming.

Bottom-Up Estimating technique is used under the processes Estimate Activity Resources and Estimate Costs.

Published Estimating Data

This is the database maintained by organization about the unit price and production rates for resources which includes man, machine and material considering different geographical locations. Using this data one can estimate the budget and the resources required to execute the project. This database will be routinely updated by the organization.

For example, for a particular human resource with specific skill and experience what he/she may charge in a specific country?

Published estimating Data is the technique used under the process Estimate Activity Resources process.

Alternative Analysis

While planning, one can find different ways to achieve the goal or carrying out an activity. Alternative Analysis technique is one of the ways to get resources in different ways to accomplish the activities. For example: different skills, different configuration of machines, automation, outsourcing, etc…

Alternative Analysis is the technique used under the process Estimate Activity Resources process.

Leads and Lags

Lead is advancing an activity and Lag is delaying an activity. This technique is used while planning when we are constructing the network diagram using by considering the dependencies. Also this technique is used during Monitoring and Controlling to bring the project on track by adjusting Lead and Lag.

Suppose you want to reach office 9 in the morning. Every day it may take about an hour to reach. So usually you start at 8 in the morning. But let us you know that tomorrow there is a blockage of road due to some rally in the usual route, you need to take alternative route. But it takes more time. So what you do? Instead of starting at 8 in the morning, you plan to start at may be 7.30 in the morning. This half an hour is called lead. You are advancing an activity.

Lag is waiting period between two activities. Once you construct ground floor, you need to wait for two days before starting the first floor. This waiting period which is 2 days is called lag.

Lead and Lag technique is used under processes like Sequence Activities, Develop Schedule and Control Schedule processes.

Dependency Determination

There are four types of dependencies to be considered while considering the sequencing namely Mandatory, Discretionary, External and Internal.

Mandatory: It is the used when it is inherent to the nature. For example construction of the wall depends on finishing of the foundation. You can’t think of the other way. This is also called as hard logic.

Discretionary: In the situation there are some activities which can be carried out either way based on the logistics availability or based on the best practices. It is based on the preference. This is also called as preferred or soft logic. For example if you want to provide the training to the operation team about the project, the training can happen after the transition or before the transition. The training can be imparted based on the logistics availability and the people.

External: This is nothing but where you are dependent on the external environment or element where you don’t have any control. For example, approval from the government organization or materials from the vendor.

Internal: Here the dependency is within the project. For example funding, resource availability, etc…

Dependency Determination technique is used under the process Sequence Activities.

Precedence Diagramming Method (PDM)

PDM is used to construct the schedule model based on the logical relationship of the activities within the project. One of the methods used under diagramming method is Activity on Node or AON. The activities are represented within the nodes and the arrow shows the relationship between the activities. One more method under diagramming method is Activity on Arrow (AOA). Here the arrow represents the activity.

There are four types of relationships used when constructing schedule model using Precedence Diagramming Method.

Finish to Start (FS): Starting of an activity depends on the finishing of the previous activity. For example starting of the second shift depends on finishing of the first shift.

Start to Start (SS): Starting of an activity depends on the starting of the other activity. Here two activities run in parallel. For example starting of the training depends on starting of the assembly of the delegates. Here I am assuming trainer need not to wait for all the delegates to come. Even one delegate is enough to start the training.

Finish to Finish (FF): Finishing of an activity depends on finishing of the other activity. Again here two activities run in parallel. For example finishing of project closing depends on finishing of lessons learned documentation. Lessons learned activity might have started earlier itself, but by the time project closing finishes lessons learned should finish or at the same time.

Start to Finish (SF): Finishing of an activity depends on starting of the other activity. For example the finishing of first shift depends on starting of the second shift.

SF is very rarely used and FS is frequently used.

Also AOA is outdated. AOA can’t use all the four types of relationships. It can use only FS relationship whereas AON uses all the four types of relationships.

Precedence Diagramming Method technique is used under the process Sequence Activities.

Rolling Wave Planning

It is a technique which is used when the things are not so clear in the beginning of the project. As we progress the clarity will be better. Rolling Wave Planning technique is like iterative approach. The work to be carried out in the near future will be planned in detail and the work to be carried out later stages will be planned at a very high level. As we approach nearer to the later work will plan in detail. It is form of progressive elaboration.

Rolling Wave Planning technique is used under Define Activities process.