Extraction Transformation and Load (ETL) – some thoughts on a large IT transfer project

In 2017 I was involved in an important work project to transfer all the records in a legacy system that was being deprecated by the vendor into another maintained system. We were in some ways fortunate because both systems had been designed by a single company and they were encouraging us to transfer. We had delayed transfer for several years already but were aware that we now had to move. The vendor did have some tools in place , had staff dedicated to such transfers and were offering favorable consultancy rates. The amount of data was not horrendous in computing terms but they were far far beyond the remit of the ability to cope with any sort of manual data correction and the system was an absolute core system upon which several departments completely depended. These were systems that all departments are in from the moment they start the work day to the end. Generally its unusual if they are down for more than 5 minutes in a month, all work pretty much stops when they stop and in no circumstances could they be down for more than a day without special dispensation and coordination to indicate to manage customer expectations.

The whole project was a success although it was challenging. Here is an outline of the steps we took. As ever order here is important in most of the steps.

Step
Inform managers of all involved sections and ensure they are on board – identify and ring fence budget

Step
Appoint project manager on vendor and client side
draw together team to perform transformation.

Step
Draft time table creation of how long it will take putting in place planning for tutorials on systems and consultancy.

Step
Request managers to put forward staff on all sides willing to be involved

Step
Identify any omissions in knowledge and start to identify how this can be remedied. Kick off and complete acquisition of said staff.

Step
Meeting with lead staff to confirm buy in. Request buy in from staff including ring fencing of holidays etc.. to ensure key staff are available at required times.

Step
Set up test systems that all individuals have access to and ensure that the old and new systems can be viewed simultaneously by individuals. Ensure that the domain specialists can identify processes that will be mirrored from the old system to the new system

Step
Give DBAs or those that will be doing data transfer access to databases of source so that they can start thinking of how they can pull out information.

Step
Training for all individuals concerned in new systems.

Step
In new system start tasking individuals with how they are going to do the simple processes – eg register a record approve a record alter a record and get reports out. If possible allow new champions to start to define things like reports.

Step
Start making up any new lookup fields compared with old lookups and also start tasking individuals with creation of reports and letter that will need to be done.

Step
Start mapping the data from old system to new system – excel spreadsheets can be used for this that show the data going from the old system and what fields they are going to go into in the new system. Divide this task up between domain users – this step needs to be done after old and new systems are on domain users machines. As part of this the applications in question should expose if possible the table and field names of the source and target fields. With the systems we were involved in this was possible both for the old and new systems.

For each form on the two systems try to identify the below

Source table.field Target table.field

Also get them to map the lookup table values if direct transfer is not possible or if alias id are used in these lookups.

Source table.field.value=Equivalent.Target table.field.value

Step
Give both mapping documents to the ETL people to allow them to start writing the queries. It is unlikely that there will be a straight transfer across from table to table. While it would be expected that field and table names will be completely different it will be expected that table structure will in certain places be different in this respect it would be good to have a really nice schema diagram of both source and target.

Step
Allow data individuals to write scripts that can be run live against present initial system – if necessary doesn’t need to be live live could copy every night and then perform on 1 day old database backend – which is what we did. This means work can go on in old system and then at a touch of a button.

Encourage DBAs to be able to run these scripts every day to ensure that running them for go live is absolutely no issue. Our scripts only took about half an hour to run so this wasn’t an issue. I was personally involved in writing the SQL for those and I had systems in place to cross tab the amount coming into each new table so I could see new records and information from the old system trickling manually into the system and then being transferred.

Step
Test data input into new system

Step
Check test data input into new system with reference to domain users.

Step
Confirm go live date ensure staff available for issues

Step
Go live to production and start all new procedures ensure staff technical and domain key players on hand to make flexible solutions to things

Step
Project review on going maintenance and improvement of new system

Step
After suitable time turn off of old system if possible.

Appropriate User Interfaces

I have three guitars 10 windsurfers and 4 bikes (5 if you count a static exercise bike) I have three regularly used computers (tablet , desktop and laptop) – four if you count my phone. My bikes are not duplicates one is for racing, one is for training, one is for commuting and the final one for mountain biking. I often use my commuting bike instead of my car. I try my hand at DIY and have got to the point of building a cupboard containing drawers only for tools I have so many tools I cannot list them all from memory.

I get the impression that companies are pushing for all applications to be pushed to the web. Fine but if you have invested in an amazing building with an amazing Local Area Network why push absolutely everything to the web? Milk your assets often the longer you leave it the more stable the web environment will be – it still continues to experience massive change. Web has its advantages but flexible cheap very rich User Interface design doesn’t seem to be it. The benefit of database driven applications today is that the backend is totally independent of the User Interface. Developing an internal local area based UI can be totally independent of building a web based user interface.

Carefully consider and don’t be afraid to use the full range of tools available to you get the backend right and then work on a very very usable front end. Users want quick usable design that fit their needs they really don’t care about the technology.

Project Management – Things that help lead to successful outcomes

FinishLine

Many roles within organisations now require good project management skills especially when it comes to implementing new IT systems and applications. But are there things that can be put in place at the beginning to improve your chance of success. I would say yes and if I am involved in a project my personal guidelines are as follows;

Step 1 : Get Stuck In
The benefit of computers is that manipulated electrons are essentially free and immortal. Try to rearrange a few. If you aren’t getting anywhere wipe them and then re-arrange them some more. Even if you are not successful you are successful in knowing that one particular arrangement cannot be achieved. You are creating a machine just like children do with Lego or engineers create with bricks and mortar except your bricks can immediately be removed and copied infinitely and each additional brick often costs nothing. In most organisations you will quickly come up against configuration and security problems. Configuration and security problems come out of nowhere often and can be project killers best to know about them up front.

Step 2 : Know your Technology
If you don’t know it at the beginning you better hope you know it at the end – go to step 1 if you are struggling with step 2 – That’s recursion for you.

Step 3 : Increment often and test constantly
Set short deadlines and try to regularly meet with client to show progress – can be frustrating if clients start going off on tangents

Step 4 : Know the Process
To date I haven’t been asked to design any systems that I have had particular difficulty in understanding the process. Undoubtedly I think this would be different if I was trying to create an application for geology exploration or for instance mapping or maybe translation. The mathematics behind those kind of applications are complicated. Most business processes tend to be remarkably simple and the simple act of normalizing the data is usually enough for me to get to grips on how the system will be used.

Step 5 : Build in redundancy
Properly normalize your data build in extra fields if you want even if they are not used – for example collecting information on individuals I always add a field for date of birth even if its not spec’d invariably someone comes along and says actually it would be useful to know what age our customers are.

Step 6 : Have privileges
There’s nothing that will slow down a project quicker if you have to hand over responsibility of tasks to uninterested individuals who are not part of the project team. Better to have those people in the team and make sure they are on board with the importance of following through with the project.

Good luck and happy hunting

Guidelines for E-mails

Not the most exciting of subjects but everyone is involved in communication whether its sorting out lunch with a friend through to organising massive engineering projects. Confusion and misinformation is always an ongoing risk resulting from bad communication which results in individuals either not getting on board with a topic or going off and doing needless work. Today I really rallied against the endless stream of emails I had been cc’d into. I realised that I am probably as guilty as others in doing this so I decided I should figure out some guidelines for tightening up my e-mail etiquette

My guidelines;

1)If you are replying delete generic titles and write a title which is more specific about what is contained in the e-mail. (Try not to use Re: if you have to state Reply )
2)Spend time making and crafting a really relevant reply which is as targeted as possible.
3)If possible delete the train wreck of replied e-mails – most of them are not read by anyone and quite often have all sorts of tags, addresses and generic images which are totally irrelevant.
4)Be economical in cc e-mails if you want to introduce others into a project – write a specific introduction e-mail for that individual explaining everything don’t just copy them into a massive e-mail and expect them to go back through and figure out what is going on.
5)If you have questions that you need answered really start with the question and explain the context.
6)Use pictures – They are useful and e-mails really support pictures very very well now.
7)If you have simple calculations from excel spreadsheets contain them as images in the e-mail attachments are annoying and take time to open up.
8)If you are working with people on a project you really need to have met the people. If they are in your building why not go and introduce yourself?
9)Hey use the phone its there it costs nothing again more important if you don’t know the person.
10)Don’t just write with questions – if you have an outcome that you think is important or you’ve received some positive feedback after project completion let the others on the project know about it.
11)Generally aim to be positive and supportive
12)If you make commitments try to remember them and stick to them.