Project delivery model
The delivery model determines whom the client awards the work to: individual contractors per trade, a general contractor taking on execution as a whole, or a total contractor who is also responsible for design. The choice is commonly treated as a question of cost, risk and influence. It is just as much a question of time.
The scheduling effect comes before the site
Between the start of the tender and the start of construction lies a phase whose length differs by model. As orders of magnitude from training practice – not as normative values:
- Separate contractors: around 185 working days until construction starts.
- General contractor: around 255 working days.
- Total contractor: around 325 working days.
Between the shortest and the longest route there are therefore some 140 working days – more than half a year before the first site installation is in place.
Where the spread comes from
Revealingly, the difference does not arise everywhere. Preparing the tender takes roughly the same time in all three models – around 75 working days. Two other phases diverge:
- Tendering: around 25 days with separate contractors, 70 with a general contractor, 100 with a total contractor – with correspondingly more rounds of questions.
- Work preparation: around 40, 60 and 80 days respectively.
The reason is plausible: the more responsibility a bidder takes on, the more they have to think through themselves before quoting – and the longer it takes them to price with commitment. The time does not disappear; it moves from the client to the bidder.
What this means for the schedule
If a handover date is promised early and the delivery model is chosen only afterwards, a decision about the model can make the schedule untenable in retrospect – without anything going wrong on site. The preliminary phase therefore belongs in the schedule, not just the construction process: tender, bidding, evaluation, award and work preparation are tasks in their own right, with durations.
In Menira this phase can be kept as a section of its own ahead of the construction start, so that the procurement route and the construction sequence stay visible in one plan.