The schedule is the start and end dates for each task, and from that the start and end date for the overall project. The end date is simply the start date plus the effort (in reality it is more complex than this – but this will do for now). The start date is determined by:
● When any predecessor tasks are finished (and do not forget external dependencies)
● When the people who are to do this task have completed previous steps they must work on
● When the people who do this task are available (i.e. not weekends, not holidays, not doing other non-project work). This is easiest if everyone is 100 per cent on the project (see the end of this section for further points on this).
Building on the example in Table 3.5, I have added two further columns to give Table 3.6. I have used a 2005 calendar to work out dates and to exclude weekends and bank holidays. Although this is not part of the plan, I have also included a notes column to help explain the new entries.
ask WBS Task PredecessorEffortWho Start EndNotes numberdescription(Delay)does it 1.1Select contractor to See sub-tasks work with 2.1.1Document needs (what 0.5Dave31 May31 MayProject starts on you want the contractor to do)Tuesday 31 May. (Monday 30 is a holiday in the UK) 3.1.2Write tender (convert 1.10.5Dave31 May31 May1.1 + 0.5 days needs to a formal tender document) 4.1.3Select possible 1.20.5Dave1 June1 June1.2 + 0.5 days contractors 5.1.4Send to possible 1.30.5Dave1 June1 June1.3 + 0.5 days contractors 6.1.5Wait for responses1.4+10 Delay2 June15 June1.4 + 10 days (Delay 10 working = 2 calendar weeks) 7.1.6Review responses1.52Dave16 June17 June1.5 + 2 days 8.1.7Select contractor1.61Dave20 June20 June1.6 + 1 day 9.2Prepare officeSee sub-tasks 2.1Design office layout1.73Contractor21 June23 June1.7 + 3 days 2.2Fit electricsSee sub-tasks 2.2.1Install new lights2.13Contractor 24 June28 June2.1 + 3 days 2.2.2Install new sockets2.12Contractor29 June30 June2.2.1 + 2 days (Predecessor is 2.1, but contractor won’t be available until completed 2.2.1). 2.3Fit carpets2.1, 3.42Contractor6 July7 JulyLatest of 2.1 and 3.4 + 2 days
2.4Install phones3.54Adam9 August12 August3.5 + 4 days 3Install furnitureSee sub-tasks 3.1Choose new furniture1.72Dave21 June22 June1.7 + 2 days 3.2Order furniture3.11Dave23 June23 June3.1 + 1 day 3.3Wait for furniture to be 3.2+20Delay24 June21 July3.2 + 20 days delivered 3.4Remove old furniture4Contractor1 July6 JulyNo predecessor, but contractor not available until completed 2.2.2 3.5Fit new furniture2.3, 3.312Contractor22 July8 AugustLatest of 2.3 and 3.3 + 12 days 4Install new PCsSee sub-tasks 4.1Choose new PCs2Mary31 May1 JuneNo predecessor, can start when project starts 4.2Select software2Mary2 June3 JuneNo predecessor, can start when project starts, but Mary not available until she has completed 4.1 4.3Order PCs and software4.1, 4.21Mary6 June6 June4.2 + 1 day 4.4Wait for PCs to be delivered+20Delay7 June4 July4.3 + 20 days 4.5Install software on PCs4.413Mary5 July21 July4.4 + 13 days 4.6Install configured PCs3.5, 4.517Mary9 August1 SeptLatest of 3.5 or 4.5 + 17 days. (29 August is a holiday) Table 3.6The schedule
The dates in the schedule measure elapsed time or duration – and not effort. Therefore don’t forget when you are working out times:
● Weekends are normally to be excluded. (So 10 working days is two calendar weeks.)
● Bank holidays are normally excluded. (So on this schedule 30 May and 29 August are excluded.)
● You need to account for personal holidays. So if Mary has 2 weeks’
holiday starting on 15 August, task 4.6 will have a two-week delay in the middle of it – so it will stretch out until 15 September. (In this plan no holidays have been assumed.)
● People may be working on other things at the same time. Often people are not available 100 per cent of the time. So if Mary is not only doing your project, but must also give 50 per cent of her time to another project, all the elapsed times for tasks she is responsible for will need to be doubled. For example, an effort of 2 days will take 4 elapsed days for someone 50 per cent available.
● Remember to consider how many days a week people are ever avail- able. In practice no one is available for 5 days a week continuously.
People always have other things to do at work. On a very short project, when you involve someone for a week or two, it is fair to assume you will get 100 per cent of their focus. Beyond this, at best you will get 4 days a week from someone once you have accounted for other things they need to do. (If you wonder what other things, add up the time you spend handling your mail, phone calls, e-mails, having coffee, in meetings, and simply walking around the office every day.)
This is really where planning software comes into its own as it will auto- matically calculate the start and end dates, and change them immedi- ately you change the length of any other task, or the availability of people to do the work – hence it can speed up the process of creating a plan. When used, planning software removes an administrative burden but the end plan will be not be better because you used it.