Step-6] Develop Project Schedule

Pre-requisite for this step:  Below deliverables should be available for this step

1.       Work Packages identified
2.       Activity list that describe each of the activities are defined
3.       Activity sequencing that describe how each of the activities are related to each other are clear
4.       Quantity, Type and category of the resources required to complete the activity is clear
5.       Estimate work periods required to complete the activities

Objective of this step: Generate project schedule by entering activities, their durations, resources, resource availabilities and logical relationships into scheduling tools like Microsoft Project Plan, Excel with planned dates for completing the project activities.

1. Outputs:

Schedule Baseline- Approved Version of Schedule Model that can be changed only through formal change control procedure - Used as a basis for comparison to actual results -

Schedule Baseline is a component of Project Management Plan

Project Schedule- The project schedule is an output of schedule model that presents linked activities planned dates, durations, duration, milestones and resources.  At the minimum, the project schedule contains planned start date and planned finish date for each activity. The project schedule remains preliminary until resource assignments are confirmed and schedule start and finish dates are established. The project schedule may be presented  in

·         Milestone Schedule:  A schedule that is detailed at Milestone level on time line scale
·         Summary Schedule:  A schedule that is detailed at Work package level on time line scale
·         Detailed schedule:  A schedule that is detailed at activity level along with relationship and their sequences on timeline scale.

The project schedule can be represented either through

n  Tabular Form similar to WBS
n  Bar Charts
n  Milestone Charts
n  Project Schedule network diagrams

Source: Project Management Body of Knowledge page (PMBOK guide 5th edition) page 183

Schedule Data- It is the collection of information for describing and controlling the schedule. To help monitoring and control the schedule, the schedule data will be useful

n  Schedule Milestones, Schedule Activities, activity attributes,
n  Assumptions and constraints
n  Resource requirements
n  Alternative schedules (worst-case, best-case, most probable)
n  Scheduling Contingency Reserves
n  Cash flow projections

Project Calendars- Identifies working days and shifts that are available for scheduled activities. It includes public holidays that are applicable all working sites where the project is being executed.

Project Management plan Updates: Updates required for
n  Schedule Management Plan
n  Schedule Baseline

Project Document Updates: Updates required for

n  Activity Resource Requirement
n  Activity Attributes
n  Calendars
n  Risk Register [ To reflect opportunities or threats perceived through scheduling assumptions]

2. Tools and Techniques:

A. Schedule Network Analysis - It generates the project schedule model. It uses Critical Path Method, Critical Chain Method, and what-if analysis, resource optimization to calculate early and late start and finish dates.  On Network diagram, it focuses on points of convergence or divergence to explore possibilities of fast tracking or crashing of the duration.

B. Critical Path Method- Network analysis technique calculates the early start, early finish, late start and late finish dates for all activities without regard to resource limitations -

Through Forward Pass, early start and finish dates are calculated. Through Backward Pass, late start and Late Finish dates are calculated.  Critical Path- Longest Path through the project network diagram - Shortest Duration a Project can complete

Total Float - Amount of time, an activity can be delayed without impacting project finish date - Normaly the activities on Critical Path have Zero total float.

Total Float = Late Start - Early Start = Late Finish-Early Finish

Source: PMI's PMBOK 5th Edition, 177 page.
 

D. Critical Chain Method: It is brings another concept called Feeding Chain. Feeding chains are non-critical network paths. In Critical Chain Method, we add duration buffers that are non-work schedule activities to manage uncertainty.

n  Project Buffer protects the target finish date from slippage on the critical path.
n  Feeding Buffers n [Placed on non-critical Path] protects from slippage on Feeding chain
Feeding Buffers are not placed on critical Path.

Source: PMI's PMBOK 5th Edition, 178 page.

E. Resource Optimization Techniques: It involves techniques to adjust Schedule Model due to demand and supply of resources. There are two widely accepted techniques.

Resource Levelling can be used when shared or critically required resources are only available at certain times, or in limited quantities - or when resources are over allocated. In this technique, start date and finish dates are adjusted based on resource constraints with the goal of balancing demand for resources with the available supply – Resource levelling can often cause the original critical path to change, usually to increase.

 

Source: PMI PMBOK 5th Edition Page 179

Resource Smoothing- In this approach, the project’s critical path is not changed and the completion date may not be delayed. In other words activities are delayed within their free and total floats. Thus, resource smoothing may not be able to optimize/balance all the resources.
 

F. Modelling techniques – What If scenario Analysis: "What if the situation represented by scenario 'X' happens - The outcome of the what-if scenario analysis can be used to assess the feasibility on the project schedule under adverse situations - This helps in preparing contingency and response plans to mitigate impact of unexpected situations.

Simulation: A model is built to assess the future with present parameters - This is to ensure we assess the future and take rights steps today - Imagine we know how we will look like and behave 20 years after, we can definitely take steps to correct outcome with present actions from today.

Monte Carlo analysis is most used simulation technique - The three possible activity duration estimates are fed into this model for all activities and activity assumptions and limitations are fed into. The Montel Carlo analysis provides possible outcomes for the total project.

G. Leads and Lags: Leads are used to advance a successor activity with respect to predecessor activity. Lags are used to delay the successor from the predecessor - Elapsed time between successors and Predecessors

H. Schedule Compression: Schedule compression techniques are used to shorten the schedule duration without reducing the project scope, in order to meet schedule constraints or imposed dates. Schedule compression includes

Crashing: A technique used to shorten the schedule duration for the least incremental cost by adding resources -Examples of crashing include approving overtime, bringing additional resources or paying to expedite delivery of critical path activities. Crashing does not always produce viable alternative but results in Increased Risk and or Cost.

Fast Tracking – A technique in which activities are performed in parallel for at least a portion of their duration. An example is constructing the foundation of the building before completing all of the architectural drawings. Fast tracking often results in rework and increased risk. It works only when activities can be overlapped to shorten the project schedule duration.

I. Scheduling Tool – Automated scheduling tools like Microsoft Project Plan contain the schedule model and expedite the scheduling process by generating start and finish dates based on the inputs of activities, network diagrams, resources and activity durations using schedule network analysis.

3. Inputs:

Schedule Management Plan - Activity List - Activity Attributes- Schedule Network diagram containing logical relationships among the activities - Activity Resource Requirements – Activity duration estimates- Resource Breakdown structure- Resource Calendars - Project Scope statements - Risk Register [List of Risks, along with results of risk analysis, risk response planning, Updates to risk register] - Resource Break Down Structure –Project Staff Assignments -  Enterprise Environmental Factors [Productivity Metrics, Duration Estimation Data, Published commercial info, Location of team members] - Org Process Assets [Historical info - Lessons Learnt- Scheduling Methodology- Project Calendars]