Many years ago when I was taking a degree course in Mechanical Engineering, I remember my first real brush with data modelling and computers. It was getting used to data input for computer programs where data had to be put in the correct format to be read by the program. In those days, input was [...]
Changes for one? In the last post we highlighted the importance of getting input from more than one person. This post looks at a variation on that. We will often get input from various parts of an organisation which need different information and different verification. As a result, some tables will be important to one [...]
The last post concluded by considering the need to get input from different interest groups when designing systems for existing or new applications. When we have a data modelling assignment, we often discuss requirements with a limited set of contacts within the client company. Data modelling is considered a little too arcane for most people, [...]
When working with new processes or projects, the main tasks are to deliver what is necessary, while constraining the scope. This is the goal in any engineering project, but it is less clear-cut for more abstract items like software, particularly when there is no definable package of tools to be replaced. […]
Introduction Once again, let’s acknowledge that modelling new processes is a much more risky business than modelling an existing process. Why, you may ask? The fundamental reason is our human desire to gild the lily. When a building, bridge, vehicle or other physical object is being designed, we have the same tendencies – the first [...]
In any data modelling, the first, most significant question, is whether we are trying to improve an existing process or model a new process – a process which does not yet exist. The approach to each is fundamentally different. […]
In the last newsletter we considered our first Django classes for our modelling of EPANET input files. This time we look at the rest of the classes that we need to replicate the tables defined in our earlier newsletters (#18, #19, #20 and #21). […]
In an earlier series of newsletters, we looked at input files for EPANET, a public domain water supply network modelling tool. To minimise the modelling required, we took as an example the simplest water supply network that I could think of – Hezekiah's tunnel in Jerusalem – and considered the tables we would need to [...]
Last week we went through the second stage of the rather painful process of setting up a simple Django example. For most people, this is not really a simple process, and if you have managed to survive through it, you have done well. A project from scratch The quick summary of beginning to set up [...]
The Django script manage.py can be used to create our new table. We pointed out in the previous newsletter that the table created will differ between databases, and this newsletter will consider some of this variation and what we can learn from it. […]