Visualizing progress

Having collected data about project progress, a manager needs some way of presenting that data to greatest effect. In this section, we look at some methods of presenting a picture of the project and its future. Some of these methods (such as Gantt charts) provide a static picture, a single snap-shot, whereas others (such as time-line charts) try to show how the project has progressed and changed through time.

The Gantt chart

One of the simplest and oldest techniques for tracking project progress is the Gantt chart. This is essentially an activity bar chart indicating scheduled activity dates

Henry Gantt (1861-1919) was an industrial engineer interested in the efficient organization of work.

and durations frequently augmented with activity floats. Reported progress is recorded on the chart (normally by shading activity bars) and a 'today cursor' provides an immediate visual indication of which activities are ahead or behind schedule. Figure 9.5 shows part of Amanda's Gantt chart as at the end of Tuesday of week 17. Code & test module D has been completed ahead of schedule and code & test module A appears also to be ahead of schedule. The coding and testing of the other two modules are behind schedule.

Gavin

Code & test module A

Purdy

Code & test module B

Justin_

Code & test module C

Gantt Chart With Slippage

Figure 9.5 Part of Amanda's Gantt chart with the 'today cursor' in week 17. The slip chart

Spencer

Code & test module D

Amanda

Specify overall system Check specifications Check module C spec

Review meetings

Figure 9.5 Part of Amanda's Gantt chart with the 'today cursor' in week 17. The slip chart

A slip chart (Figure 9.6) is a very similar alternative favoured by some project managers who believe it provides a more striking visual indication of those activities that are not progressing to schedule - the more the slip line bends, the greater the variation from the plan. Additional slip lines are added at intervals and, as they build up, the project manager will gain an idea as to whether the project is improving (subsequent slip lines bend less) or not. A very jagged slip line indicates a need for rescheduling.

Ball charts

A somewhat more striking way of showing whether or not targets have been met is to use a ball chart as in Figure 9.7. In this version of the ball chart, the circles indicate start and completion points for activities. The circles initially contain the original scheduled dates. Whenever revisions are produced these are added as second dates in the appropriate circle until an activity is actually started or

Planned time (week numbers) » 12 I 13 I 14 I 15 I 16 I

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Planned time (week numbers) » 12 I 13 I 14 I 15 I 16 I

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Slip Chart

Figure 9.6 The slip chart emphasizes the relative position of each activity.

Gavin

Code & test module A

Purdy

Code & test module B

Justin

Code & test module C

Spencer_

Code & test module D

Amanda

Specify overall system Check specifications Check module C spec

Review meetings

Figure 9.6 The slip chart emphasizes the relative position of each activity.

completed when the relevant date replaces the revised estimate (in bold italic in Figure 9.7). Circles will therefore contain only two dates, the original and most recent target dates, or the original and actual dates.

Where the actual start or finish date for an activity is later than the target date, the circle is coloured red (dark grey in Figure 9.7) - where an actual date is on time or earlier than the target then the circle is coloured green (light grey in Figure 9.7).

Such charts are frequently placed in a prominent position and the colour coded balls provide a constant reminder to the project team. Where more than one team is working in close proximity, such a highly visible record of achievement can encourage competitiveness between teams.

Another advantage of ball charts over Gantt and slip charts is that they are relatively easy to keep up to date - only the dates and possibly colours need to be changed, whereas the others need to be redrawn each time target dates are revised.

The timeline

One disadvantage of the charts described so far is that they do not show clearly the slippage of the project completion date through the life of the project. Knowing the current state of a project helps in revising plans to bring it back on target, but analysing and understanding trends helps to avoid slippage in future projects.

The timeline chart is a method of recording and displaying the way in which targets have changed throughout the duration of the project.

Figure 9.8 shows a timeline chart for Brigette's project at the end of the sixth week. Planned time is plotted along the horizontal axis and elapsed time down the vertical axis. The lines meandering down the chart represent scheduled activity

David Youll in Making Software Development Visible, John Wiley & Sons, 1990, describes a version of the ball chart using three sets of dates and part-coloured balls.

Baily Balls Progress Project Management
System (20/5/99

21/5/99/ Integration V 28/5/99 Figure 9.7 The hall wall chart provides an incentive for meeting targets.

completion dates - at the start of the project analyse existing system is scheduled to be completed by the Tuesday of week 3, obtain user requirements by Thursday of week 5, issue tender, the final activity, by Tuesday of week 9, and so on.

At the end of the first week Brigette reviews these target dates and leaves them as they are - lines are therefore drawn vertically downwards from the target dates to the end of week one on the actual time axis.

At the end of week two, Brigette decides that obtain user requirements will not be completed until Tuesday of week six - she therefore extends that activity line diagonally to reflect this. The other activity completion targets are also delayed correspondingly.

By the Tuesday of week three, analyse existing system is completed and Brigette puts a blob on the diagonal timeline to indicate that this has happened. At the end of week three she decides to keep to the existing targets.

At the end of week four she adds another three days to draft tender and issue tender.

Note that, by the end of week six, two activities have been completed and three are still unfinished. Up to this point she has revised target dates on three occasions and the project as a whole is running seven days late.

Exercise 9.2 By the end of week 8 Brigette has completed planning the office layout but finds that drafting the tender is going to take one week longer that originally anticipated. What will Brigette's timeline chart look like at the end of week 8? If the rest of the project goes according to plan, what will Brigette's timeline chart look like when the project is completed?

Milestone Slippage

MliWTF

MTWTF

MTWTF

MTWTE.

Planned Time Week number

Brigette's timeline chart contains only the critical activities for her project; • indicates actual completion of an activity.

For the sake of clarity, the number of activities on a timeline chart must be limited. Using colour helps to distinguish activities, particularly where lines cross.

Figure 9.8 Brigette 's timeline chart at the end of week six.

The timeline chart is useful both during the execution of a project and as part of the post-implementation review. Analysis of the timeline chart, and the reasons for the changes, can indicate failures in the estimation process or other errors that might, with that knowledge, be avoided in future.

Project Management Made Easy

Project Management Made Easy

What you need to know about… Project Management Made Easy! Project management consists of more than just a large building project and can encompass small projects as well. No matter what the size of your project, you need to have some sort of project management. How you manage your project has everything to do with its outcome.

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