Can you imagine starting a long car trip toan unfamiliar destination without a map ornavigation system?
You're pretty sure you have to make someturns here and there, but you have no ideawhen or where, or how long it will take to getthere.
You may arrive eventually, but you runthe risk of getting lost, and feeling frustrated,along the way.
Essentially, driving without any idea ofhow you're going to get there is the same asworking on a project without a schedule.
No matter the size or scope of yourproject, the schedule is a key part of projectmanagement.
The schedule tells you when each activityshould be done, what has already beencompleted, and the sequence in which thingsneed to be finished.
Luckily, drivers have fairly accurate tools theycan use. Scheduling, on the other hand, is not anexact process. It's part estimation, part prediction,and part 'educated guessing.‘ Because of theuncertainty involved, the schedule is reviewedregularly, and it is often revised while the project isin progress.
It continues to develop as the project movesforward, changes arise, risks come and go, and newrisks are identified. The schedule essentiallytransforms the project from a vision to a time-basedplan.
Project Schedule also help you do the following:
They provide a basis for you to monitor and controlproject activities
They help you determine how best to allocate resourcesso you can achieve the project goal
They help you assess how time delays will impact theproject
You can figure out where excess resources are availableto allocate to other projects
They provide a basis to help you track project progress
Personal and project calendars – Understandingworking days, shifts, and resource availability iscritical to completing a project schedule.
Description of project scope – From this, you candetermine key start and end dates, majorassumptions behind the plan, and key constraintsand restrictions. You can also include stakeholderexpectations, which will often determine projectmilestones.
Project risks – You need to understand this to makesure there's enough extra time to deal withidentified risks – and with unidentified risks (risksare identified with thorough Risk Analysis).
Lists of activities and resource requirements –It'simportant to determine if there are otherconstraints to consider when developing theschedule. Understanding the resource capabilitiesand experience you have available – as well ascompany holidays and staff vacations – will affectthe schedule.
Schedule Network Analysis – This is a graphicrepresentation of the project's activities, the time ittakes to complete them, and the sequence in whichthey must be done.
Project management software is typically used tocreate these analyses – Gantt charts and PERTCharts are common formats.
Critical Path Analysis – This is the, and
calculating the 'best line' – or critical path – to takeso that you'll complete the project in the minimumamount of time.
The method calculates the earliest and latestpossible start and finish times for project activities,and it estimates the dependencies among them tocreate a schedule of critical activities and dates.
Schedule Compression – This tool helps shorten thetotal duration of a project by decreasing the timeallotted for certain activities. It's done so that youcan meet time constraints, and still keep the originalscope of the project. You can use two methods here:
Crashing – This is where you assign more resourcesto an activity, thus decreasing the time it takes tocomplete it.
This is based on the assumption that the timeyou save will offset the added resource costs.
Fast-Tracking – This involves rearranging activities toallow more parallel work. This means that thingsyou would normally do one after another are nowdone at the same time.
However, do bear in mind that this approachincreases the risk that you'll miss things, or fail toaddress changes.
These activities need to be completed in asequence, with each stage being more-or-less completed before the next stage canbegin. These are 'sequential' activities.
Other activities are not dependent oncompletion of any other tasks. You can dothese at any time before or after a particularstage is reached. These are non-dependentor 'parallel' tasks.
Step 1. List all activities in the planFor each activity, show the earliest
start date, estimated length of time itwill take, and whether it is parallel orsequential.
If tasks are sequential, showwhich stage they depend on.
Task Earliest start Length TypeDependent
on...
A. High level analysis Week 0 1 week Sequential
B. Selection of hardware platform Week 1 1 day Sequential A
C. Installation and commissioning of hardware
Week 1.2 2 weeks Parallel B
D. Detailed analysis of core modules Week 1 2 weeks Sequential A
E. Detailed analysis of supporting modules
Week 3 2 weeks Sequential D
F. Programming of core modules Week 3 2 weeks Sequential D
G. Programming of supporting modules Week 5 3 weeks Sequential E
Task Earliest start Length TypeDependent
on...
H. Quality assurance of core modules Week 5 1 week Sequential F
I. Quality assurance of supporting modules Week 8 1 week Sequential G
J. Core module training Week 6 1 day Parallel C,H
K. Development and QA of accounting reporting Week 5 1 week Parallel E
L. Development and QA of management reporting
Week 5 1 week Parallel E
M. Development of Management Information System
Week 6 1 week Sequential L
N. Detailed training Week 9 1 week Sequential I, J, K, M
Critical Path Analysis are presented using circle and arrow diagrams. In these,circles show events within the project, such as the start and finish of tasks.
The number shown in the left hand half of the circle allows you to identify eachone easily. Circles are sometimes known as nodes.
An arrow running between two event circles shows the activity needed tocomplete that task.
A description of the task is written underneath the arrow. The length of the taskis shown above it. By convention, all arrows run left to right. Arrows are alsosometimes called arcs.
This shows the start event (circle 1), and thecompletion of the 'High Level Analysis' task(circle 2).
The arrow between them shows the activity ofcarrying out the High Level Analysis. This activityshould take 1 week.
Here the activities of 'Select Hardware' and 'Core Module Analysis' cannot bestarted until 'High Level Analysis' has been completed. This diagram also bringsout a number of other important points:
Within Critical Path Analysis, we refer to activities by the numbers in the circlesat each end. For example, the task 'Core Module Analysis' would be calledactivity 2 to 3. 'Select Hardware' would be activity 2 to 9.
Activities are not drawn to scale. In the diagram above, activitiesare 1 week long, 2 weeks long, and 1 day long. Arrows in this caseare all the same length.
In the example above, you can see a second number in the top,right hand quadrant of each circle. This shows the earliest starttime for the following activity. It is conventional to start at 0. Hereunits are whole weeks.
Here activity 6 to 7 cannot start until theother four activities (11 to 6, 5 to 6, 4 to 6,and 8 to 6) have been completed.
The program (or project) evaluation and
review technique, commonly abbreviated
PERT, is a statistical tool, used in project
management, which was designed to
analyze and represent the tasks involved in
completing a given project.
First developed by the United States Navy
in the 1950s, it is commonly used in
conjunction with the critical path method
(CPM).
The program (or project) evaluation and
review technique, commonly abbreviated
PERT, is a statistical tool, used in project
management, which was designed to
analyze and represent the tasks involved in
completing a given project.
First developed by the United States Navy
in the 1950s, it is commonly used in
conjunction with the critical path method
(CPM).
ActivityPredecess
or
Time estimatesExpected
timeOpt. (O) Normal (M) Pess. (P)
A — 2 4 6 4.00
B — 3 5 9 5.33
C A 4 5 7 5.17
D A 4 6 10 6.33
E B, C 4 5 7 5.17
F D 3 4 8 4.50
G E 3 5 8 5.17
A node like this one (from Microsoft Visio) can be used
to display the activity name, duration, ES, EF, LS, LF, and
slack.
A tools use to determine
critical activities for a project.
It can be used to improve a
project schedule and evaluate
progress.
In PERT Chart, the longest
path is referred to as the critical
path, it is defined as the path
that will cause the whole
project fall behind if even one
day’s delay is encountered on
it.
It is essential that the systems
analyst carefully monitor the
activities on the critical path so as
to keep the entire project on time
or even shorten the project length
if warranted.
It is the leeway to fall behind
somewhat on critical paths.
ActivityPredecess
or
Time estimatesExpected
timeOpt. (O) Normal (M) Pess. (P)
A — 2 4 6 4.00
B — 3 5 9 5.33
C A 4 5 7 5.17
D A 4 6 10 6.33
E B, C 4 5 7 5.17
F D 3 4 8 4.50
G E 3 5 8 5.17
Activity Predecessor Duration
A. Conduct Interviews None 3
B. Administer Questionnaires A 4
C. Read Company Reports None 4
D. Analyze Data Flow B,C 8
E. Introduce Prototype B,C 5
F. Observe Reaction to Prototype E 3
G. Perform Cost/ Benefit Analysis D 3
H. Prepare Proposal G 2
I. Present Proposal H 2
10
20
40
5030 8060 70
A,3
C,4
B,4
D,8
E,5 F,3
G,3 H,2 I,2
Determining Paths:There are 4 Paths10-20-30-50-60-70-8010-20-30-40-60-70-8010-30-50-60-70-8010-30-40-60-70-80
10-20-30-50-60-70-80 is the longest path with takes 22 days which is the critical path, while others are set to be slack paths
