You must start by writing a detailed description of the problem. What is the scenario? The location? Who is involved? What data are involved? How are the data processed? What are the outputs from the current system? Give examples of tasks that people carry out.
Write about the problems that the current user faces. This implies a detailed knowledge of the system that is only possible after your investigation, in which case write out the list of problems after that section.
Describe the user's requirements. Again, you may only know what this is after detailed investigation so place this after the problems - it follows logically. The user's requirements will be things like: store data on object or person; enter data into system in a way that is easy and accurate - this opens up the way for drop-down lists and validation routines later; produce an input form that is easy to use and provides buttons for common tasks such as next, previous, print, query, etc; produce outputs that include information on objects or people; produce address labels, booklets leaflets, etc;
To qualify for 4/4 you must define a problem that is complex - requires two pieces of software and automatic transfer of data by mail merge (or 'catalogue merge' in Publisher).
Collect information from potential users, and justify the method used, compared with alternatives.
Four methods: interview, questionnaire, document search, observation. Cover at least two of these, preferably with two users of your system. Write detailed notes on each technique, choose the ones that suit your investigation and explain why you have chosen them.
You could carry out some of these by email or phone. Produce evidence of your investigation - hand-written notes, photographs, emails. Get signatures on your material to verify it. Notes should be in note form, there is no need to write them up neatly. Copy them up into your documentation but always include the hand-written notes. You need to convince the moderators that you have carried out the work you claim.
You must write about inputs, processing and outputs in the current system. An input is a question: which people have birthdays next month? Which items are below the re-stock level?
Processing is how the questions are answered e.g. look through address book to check everyone's birthdate (takes time: easier when computerised); e.g. count items on shelf and compare with re-order level in a book.
Outputs: what form do the outputs take e.g. a list of people with birthdays next month; a list of people coming to a party or wedding, a list of items to re-order with names of suppliers.
Write an outline of the hardware that will be required e.g. a desktop PC and a printer. Likewise the software e.g. a database or spreadsheet and a word processor or DTP package. Explain why you think a desktop is more appropriate than a laptop (or vice versa), why a laser printer rather than an inkjet and why a database rather than a spreadsheet. You can leave detailed choices until Design. This is the first point at which items of hardware and software should be mentioned.