Topic 4 - Cash Flow and Work Breakdown Structure Item

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CSCI 714: Software Project Planning and Estimation

Lecture 4B: Work Breakdown Structure

Gursimran Singh Walia

North Dakota State University

[email protected]

The Work Breakdown Structure

A work breakdown structure (WBS) is an outcome-oriented analysis of the work involved in a project that defines the total scope of the project
It is a foundation document in project management because it provides the basis for planning and managing project schedules, costs, and changes

Approaches to Developing WBSs

Using guidelines: Some organizations, like the DOD, provide guidelines for preparing WBSs
The analogy approach: It often helps to review WBSs of similar projects
The top-down approach: Start with the largest items of the project and keep breaking them down
The bottoms-up approach: Start with the detailed tasks and roll them up

Basic Principles for Creating WBSs*

1. A unit of work should appear at only one place in the WBS.

3. A WBS item is the responsibility of only one individual, even though many people may be working on it.

4. The WBS must be consistent with the way in which work is actually going to be performed; it should serve the project team first and other purposes only if practical.

5. Project team members should be involved in developing the WBS to ensure consistency and buy-in.

6. Each WBS item must be documented to ensure accurate understanding of the scope of work included and not included in that item.

7. The WBS must be a flexible tool to accommodate inevitable changes while properly maintaining control of the work content in the project according to the scope statement.

*Cleland, David I. Project Management: Strategic Design and Implementation, 1994

Good WBS Design Principles

The 100% Rule
The WBS defines 100% of the work of the project
Anything that isn’t defined in the WBS is outside the scope of the project.
The work content on any item is the sum of what is included under that work item
Upper Levels are Planned outcomes (deliverables), not planned actions
Ends of WBS include the activities needed to create the project deliverables
Mutually-exclusive elements
Work should only appear in one place in the WBS
WBS must be consistent with the way the project will be performed and controlled
Must be easy to update

WBS Role

Partition the major project deliverables into smaller components to improve the accuracy of cost estimates
Provide a mechanism for collecting actual costs
Provide a mechanism for performance measurement and control

Why create a WBS?

Cost Estimating
Cost Budgeting
Resource Planning
Risk Management Planning
Activity Definition

Scheduling

Scheduling forces:
Quantification of discrete effort
Placement of tasks in proper relationship
Two most common scheduling methodologies
Bar Charts (aka Gantt Charts)
Critical Path Method (CPM) using Precedence Diagramming Method (PDM)

Bar / Gantt Charts Defined:

Analyze and specify the basic approach in execution
Segment into reasonable number of activities
Estimate the time required to perform each activity
Manually places activities in time order
Sequential performance
Parallel performance
Adjust to specified completion time

Bar / Gantt Charts Advantages:

Plan, schedule and progress are all depicted graphically on a single chart
Easily read
Provides simple way to schedule small undertaking
Provides summary display of more detailed plans and schedules
Best used for management briefings

Bar / Gantt Charts Disadvantages:

Planning and scheduling are considered simultaneously
Simplicity precludes sufficient detail for timely detection of slippages
Activity dependencies cannot adequately be shown
Difficult to determine how activity progress delays affect project completion
Difficult to establish and maintain for large projects.

Bar / Gantt Chart Sample

Planned Progress

Actual Progress

Ahead of Schedule

Behind Schedule

Time Now

Completed Task

Microsoft Project WBS

Tools – Options – View – Show outline number

1. Start new project

Turn on the Project Guide
On the Tools menu, click Options, and then click the Interface tab.
In the Project Guide settings section, select the Display Project Guide check box.
Manually set up a new project

Microsoft Office Project provides a Project Guide with easy-to-follow instructions to help you set up a new project.

Project – Project Information…
or View – Turn on project guide…

http://office.microsoft.com/en-us/project/HA102639631033.aspx

Priority Indicates how readily tasks in the current project are delayed (delay: The amount of time between the scheduled start of a task and the time when work should actually begin on the task; it is often used to resolve resource overallocations. There are two types of delay: assignment delay and leveling delay.) when resources are leveled (leveling: Resolving resource conflicts or overallocations by delaying or splitting certain tasks. When Project levels a resource, its selected assignments are distributed and rescheduled.) across multiple projects. Type or select a number between 0 and 1000, with the higher number indicating a higher priority (priority: An indication of a task's importance and availability for leveling [that is, resolving resource conflicts or overallocations by delaying or splitting certain tasks]. Tasks with the lowest priority are delayed or split first.) project. Setting the project's priority to 1000 means that resources in the project will not be leveled. When leveling, Project considers project-level priorities before task-level priorities.

Tools - Options

2. Tasks

There are four major types of tasks:

1. Summary tasks - contain subtasks and their related properties

2. Subtasks - are smaller tasks that are a part of a summary task

3. Recurring tasks - are tasks that occur at regular intervals

4. Milestones - are tasks that are set to zero duration and are like interim goals in the project

Add tasks

To display outline numbers, you can add the Outline Number field to a table or sheet view, or you can choose to display the outline numbers next to the task names. To display the outline numbers next to the task names, on the Tools menu, click Options, and then click the View tab. Under Outline options, select the Show outline number check box.

Insert new task

Time DurationAbbreviation

Minute m–appears as min in the project plan

Hour h–appears as hr in the project plan

Day d–appears as day in the project plan

Week w–appears as wk in the project plan

Month mo–appears as mon in the project plan

Outlining tasks

Advantages of Outlining: (Initiating, planning, executing, controlling, closing)

• It creates multiple levels of subtasks that roll up into a summary task

• Collapse and expand summary tasks when necessary

• Apply a Work Breakdown structure

• Move, copy or delete entire groups of tasks

Tools – Options… - check “Show project summary task”

Predecessor

You now have a duration for each of the tasks but they all start on the same day. Obviously, you will have to specify the sequence of the tasks and the links between them. In MS Project a task that must be completed before another task can start is called a predecessor. The first task has no predecessor and each of the following tasks has to have at least one. In some cases a task may have several predecessors meaning that several tasks have to be completed before that one can start. In other cases a task may be predecessor to several others - its completion can allow several other tasks to start.

Tasks can be linked in four ways

Finish-Start F-S
Task 1 must finish before Task 2 can start
Start-Start S-S
Task 1 and Task 2 must start at the same time
Finish-Finish F-F
Task 1 and Task 2 must finish at the same time
Start-Finish S-F
Task 2 cannot finish until the start of Task 1

To link tasks in FS dependency:

1. Select the tasks you want to link. Tasks with a lower ID number are taken as predecessors, but if you want to set the order of tasks yourself, select tasks by holding Control while you click the tasks in order.

2. Click Link Tasks button on Standard Tool bar or choose Edit > Link tasks or Control+F2.

Summary tasks can be linked to other summary tasks or to subtasks between summary groups. Subtasks can be linked to each other too.

To unlink tasks, select tasks and click the Unlink Task in the Standard Tool bar.

Do not attempt to remove a link by deleting a cell in the predecessor's column and pressing delete as this will delete the entire task.

b. Delayed and Overlapped Links:

Sometimes tasks may be dependent on other factors causing a delay time or an overlap time, necessitating a lag or lead-time to be incorporated in a link. Lag and lead-time can be entered as units of time or as a percentage of the duration of the predecessor.

Double-click a task and open the Task Information dialog box.

2. Click the predecessor tab.

3. Select the lag/lead field.

4. Enter a number or a percentage in the cell.

5. Click OK.

The Split task button splits tasks that may be completed in parts at different times with breaks in their duration times.

The AutoLink feature is enabled by default and keeps linked tasks intact when they are linked in the FS dependency. It can be disabled in the Options dialog box if necessary.

Constraints

Certain tasks need to be completed within a certain date.
Intermediate deadlines may need to be specified.
By assigning constraints to a task you can account for scheduling problems.
There are about 8 types of constraints and they come under the flexible or inflexible category.

To apply a constraint:

1. Open the Task Information dialog box.

2. Click the Advanced tab and open the Constraint type list by clicking on the drop-down arrow and select it.

3. Select a date for the Constraint and click OK.

Flexible constraints (demarcated by a red dot in Microsoft Project 2000) restrict scheduling to a great extent whereas flexible constraints (blue dot) allow Project to calculate the schedule and make appropriate adjustments based on the constraint applied.

Inflexible constraints can cause conflicts between successive and preceding tasks at times and you may need to remove such a constraint.

b. To remove a constraint and apply an ASAP/ALAP constraint:

1. Select the tasks by holding Control and clicking on them in the order you want.

2. Click Task Information button on the Standard Toolbar and the Multiple task dialog box opens.

3. Click the Advanced tab and click the drop down arrow to open the constraint type list.

4. Choose ASAP if the project has been scheduled from the Start date and ALAP (As late as possible) if it has been scheduled from the Finish date.

5. Click OK.

Select Tools > Options > Schedule and clear the 'Tasks will always honor their constraint dates' checkbox.

Set deadline date instead of adopting an inflexible constraint. Setting a task deadline does not affect the task schedule in any way. If a deadline passes without the task being completed Project indicates it in the Indicator column (a downward pointing arrow in the Gantt Chart view).

3. Managing task

Double click on task

The degree of completion of each of the tasks.

You could do that every day as you go along. As soon as something starts to go off track, you can react and adjust accordingly.

It would be too long to go into the details of how to compensate for delays and so on.
Priority Indicates how available a task is for delay (delay: The amount of time between the scheduled start of a task and the time when work should actually begin on the task; it is often used to resolve resource overallocations. There are two types of delay: assignment delay and leveling delay.) during resource leveling (leveling: Resolving resource conflicts or overallocations by delaying or splitting certain tasks. When Project levels a resource, its selected assignments are distributed and rescheduled.). Enter a number between 0 and 1000, with the higher number indicating a higher priority (priority: An indication of a task's importance and availability for leveling [that is, resolving resource conflicts or overallocations by delaying or splitting certain tasks]. Tasks with the lowest priority are delayed or split first.) task. The higher the priority, the less likely a task will be delayed for resource leveling. Set the priority to 1000 (do not level) if you don't want Office Project 2007 to delay this task at all when leveling.

Hide task bar Hides the task bar for the selected tasks when viewing the Gantt Chart or Calendar views. To display hidden task bars for the selected tasks, clear this check box. In the Gantt Chart view, if the task is rolled up, both the task bar and the rollup symbol on the summary bar are hidden. If the task is a summary task and subtasks are rolled up to it, only the summary bar is hidden. By default, this check box is cleared.

Roll up Gantt bar to summary Specifies whether you want the subtasks you selected rolled up to the summary task bar so that the bar displays symbols that represent subtask dates. If you select a summary task, this check box is called Show rolled up Gantt bars. Clear this check box to hide the symbols for rolled up tasks on the summary task bar. By default, this check box is cleared.

Defining a Timeline

Find an optimistic value, D(o),
a pessimistic value, D(p) and
a realistic value, D(r) .
Then: Duration = ( D(o) + D(p) + 4 x D(r) ) / 6

The importance of tracking progress

Techniques to manage projects effectively:
Critical Path Management (CPM) and
Program Evaluation and Review Techniques (PERT).
They are similar and you will now often find the technique referred to as: CPM/PERT.
The technique involves using network models to trace the links between tasks and to identify the tasks which are critical to meeting the deadlines.
Once you've identified the critical path, any delay on any part of the critical path will cause a delay in the whole project.
It is where managers must concentrate their efforts.
In MS Project, you use the Tracking Gantt diagram to show the critical path in red and you can see the PERT diagram by looking at the Network view.

Gantt Chart View – critical path

A Gantt chart is a type of bar chart that illustrates a project schedule.
Critical path: View – More views… - Detail Gant

Henry Gantt used graphical bars in his industrial management studies to compare and contrast timeframes. In Microsoft Project, graphical bars are paired with a spreadsheet to give the Gantt Chart View.

PERT diagram - Network view

Views

Views allow you to examine your project from different angles based on what information you want displayed at any given time.
You can use a combination of views in the same window at the same time.
Project Views are categorized into two types:

• Task Views (5 types)

• Resource Views (3 types)

Saving a baseline

Baseline plan: The original project plans used to track progress on a project.
The baseline plan is a snapshot of your schedule at the time that you save the baseline and includes information about tasks, resources, and assignments.
You can set a baseline for your project, enabling you to compare your progress with the original plan and any additional baselines you set at milestones throughout your project.

Saving a Baseline

Tools – Tracking – Save Baseline…

http://office.microsoft.com/home/video.aspx?assetid=ES102776241033&width=1024&height=768&startindex=0&CTT=11&Origin=HA102751251033&app=WINPROJ&ver=12

On the View menu, click Tracking Gantt.

On the View menu, point to Table, and then click Variance.

RESOURCES

Manage the project resources:

Resources are of three types:
work resources, material resources and cost resources.
Work resources complete tasks by expending time on them. They are usually people and equipment that have been assigned to work on the project (you track their participation by the amount of time they spend).
Material resources are supplies and stocks that are needed to complete a project. You assign material resources by the quantity that you need: two tons of gravel or 300 gallons of diesel fuel, for instance. Because materials aren't measured by time, quantities usually affect only the cost of your project. Materials affect dates or duration only when you have to wait for those materials to become available.
Cost. Cost resources are the new kid on the Project 2007 block, and they're strictly cost; no time, no quantities—just dollars. Expenses, such as travel or fees, increase the project price tag, but they aren't associated with work or material resources.

You must start by identifying the resources available along with their costs.
Resource costs will be multiplied by duration to calculate project costs.
You have to open the Resource sheet to specify the project resources and costs.

people
equipment
supplies

Resources are of two types - work resources and material resources.

Work resources complete tasks by expending time on them. They are usually people and equipment that have been assigned to work on the project.

Material resources are supplies and stocks that are needed to complete a project.

A new feature in Microsoft Project 2000 is that it allows you to track material resources and assign them to tasks.

You will need people to accomplish all those tasks that you've identified. Those people are resources that you have to manage well in order to achieve the project's objectives.

You may also need some material resources - equipment , supplies, specialized environments - that you will have to schedule and pay for.

You can easily include the management of resources in MS Project along with the tasks because, after all, the resources are essential to the accomplishment of the tasks in the first place.

You must start by identifying the resources available along with their costs.
Resource costs will be multiplied by duration to calculate project costs.

You have to open the Resource sheet to specify the project resources and costs

The Max Unit's column contains the maximum capacity for which a work resource is available to accomplish any tasks in a certain time period. The default format is the percentage format. For example, if the assigned units are 100% this will imply that this resource will work for all the eight hours in a normal working day. If the assigned units are 50%, then this resource will work for four hours a day. In the case of a resource pool consisting of 5 workers, their maximum units will be 500% or a decimal value of 5.

Fields in the Resource Sheet may be blank or contain different types of information depending on the type of resource. For example, a work resource doesn't have a Material label, and costs are calculated initially as dollars per hour. Material resources have a cost per unit—per pound, gallon, or piece—and the Material label field defines the units. Cost resources receive a value only when you assign them to tasks.

You assign resources, people or material, to each of the tasks.

A task may have several resources.

To track costs, you insert a Cost column next to the Resources column.

When you assign the resources to each task, the costs will be calculated an displayed.

Use the Detail Gantt view to find slack (float)

On the View menu, click More Views.
In the Views list, click Detail Gantt, and then click Apply.
On the View menu, point to Table, and then click Schedule. In the chart portion of the view, slack appears as thin bars to the right of tasks, with slack values adjoining the regular Gantt bars.

Jan07

Feb07

Mar07

Apr07

May07

Jun07

Status Date: 02/Mar/2007

WBS Description

Sample Project Plan

1 Literature Search

2 Concepts Development

3 Lab Models

4 Design

5 Prototype