Substructure Programme
A programme tells you when an activity starts, the duration and end date. It also shows you how activities link with one another.
A programme is usually written by a Project Planner before works start on site.
Many softwares can be used to write programmes, some of the popular ones are ASTA Power Projects and Primavera P6.
I recommend becoming familiar with the programme for your project and analysing how long the programme allows for Substructure activities before they start on site.
Example Pre-Construction Programme
The simplified example above represents what information you can find in a Substructure programme before construction starts.
Things to note:
The start date for an activity is where the first ‘X’ or start of a ‘bar’ is. For example, the tender enquiry starts from 23rd Jan and 6th Mar is when the Substructure subcontractor should begin mobilising to site.
The duration of the activity is the length of the bar. The main contractors have five days to review design, and there are a total of seven weeks for the Commercial process.
The end date for an activity is where the last ‘X’ or end of a bar is. E.g. Subcontractor order should be issued by 2nd Mar.
Construction Programme
Once the design and procurement is complete for the Substructure package, and they have mobilised to site the programme for works may look similar to the below:
Example Substructure Construction Programme
Mobilisation – this is the period of time a subcontractor needs to start works once an order has been signed. If they receive an order on 2nd Mar as programmed, they have a period of 1 weeks to start operations.
Blinding – a thin layer of concrete (usually 50mm) applied to a surface, to provide protection and a smooth base for subsequent construction works.
Lag – the amount of time between one activity starting and the next. For example, Excavation of the tower crane base is programmed to take one week. The excavation for the lift shaft can begin 3 days into these works – this is the lag. It is based on what is logistically possible on site.
Links Explained
Some types of programme links
Links – these are represented by the black arrow and show the relationship between two activities. E.g. Main contractor review of the design drawings starts the day after structural engineers design finishes.
There are a number of other links possible including: Start-to-start, lagged start and finish and negative lag. There are also lagged start-to-start, finish-to-finish, must start/must finish links.
Tips
A good exercise to do would be to maintain an up-to-date concrete as-built register. An example of this can be found in our Substructure Quality post.
You may hear the term programme drop line used. This displays on the programme planned vs. actual progress.
Definitions
Project Planner – Individual responsible for scheduling out works to be carried out efficiently
Tender Enquiry – document outlining works to be conducted. Sent out to contractors for pricing
Procurement – Subcontractor procurement is the process of hiring external parties to perform specific tasks or services within a larger project or contract
As-built – record of what works were carried out on site. Often compared to the original plan for context.
Posts to Follow
We plan to go into more details about Substructure and add a section on:
- Commercial
Please let us know if you found this post useful using the chat function. We’d love to hear from you – is there anything in particular you’d like for us to focus on next?