Section 1 For your HRIS (data) person
Start at the Finish?What do you want to deliver?
"Employee benefit statements" is too vague."Employee benefit statements with a1...z33.", is better.  
If you know exactly what you want, then it is easy to 'back into' (derive the data items) that need to be collected.
But now, your goals are probably not that precise.  That's OK.  We'll start General, then refine the list.
Your Employee Benefit Statements Goals will eventually become concrete - the sooner the better.  
As your Communication Goals solidify, so will the Employee Benefit Statements Data Requirements.
Census (General)employee _iddivisiondeptlocationemployee _lastemployee _firststreet_address_1street_address_2citystatezipemployee _pay_typeemployee _pay_freqpay_period_hoursemployee _statusemployee birth_dateorig_hire_dateseniority_date
1) Multiple Tables (or xls) are fine2) CSV, Tab Separated, Pipe, User defined or xls. 3) Required - EOL (end of line) between employee or data rows/records.  4) Required - Column headers (names) for each employee or benefit table.5) Required- Descriptive def for each Column header.6) Helpful - Benefit CODES Tables with column descriptors7) Helpful - Detail on any Known Column or employee constraints8) Helpful - Relations diagram (hand drawn is fine)9) Required - SSN employee 'file' = {SSN, name, EE_ID, EEaddress}.  SSN (9 char) should only appear in this file.  ENCRYPT his file.10) Do not - Send EBCDIC.  Convert to ASCII.11) Do - place all files in 1 folder, then zip, encrypt.
12) Do - request email receipt.13) Avoid- Reports lacking employee & benefit keysExample:
EE_ID would have been helpful as it would likely be the linking key field to the census_table.  
ee_id   ben    code   eeded   freq1234   med     028    33.42     26             den     003      7.15     26             vsn     002      1.86     26             life     044      0.00     26
Example12345petrolwidgetsnorthHEMMAHENRY123 ANYWHERE LN.APT # 99ROCHESTERNY14611S2680FT11/12/19517/9/198811/1/1988
Benefits (General)employee _idemployee _lastemployee _firstbenefit _typebenefit _descbenefit type_codebenefit _type_descemployee _dedemployee _ded_freq
Example12345HEMMAHENRY01MEDICAL11SINGLE54.2226
Here's how it worksSince you probably do not know the precise, End Result for your employee benefit statements, we'll start with the 'basics' and build as we go.  
You may know you are going to "Benefit Statements Land" but do not know the exact 'Street Address'.  
Don't give your HRIS folks lengthy directions until you know your destination.
Here's how it should work:1) Your HRIS person gathers 'sample data' which we'll use to set up a sample database. This will also 'test' the very basics under Section 1.2) We receive your Content Source Documents & review, comparing these written documents to your Sample Tables and data.  This usually uncovers questions.3) We also use your requested Styling & Images along with your Content Source Docs to begin writing the initial 'Copy' and combining to begin creating a Sample Template.  This Template will be the preliminary design for your Project's output. Meanwhile, we are working on a Sample Template.4) We complete the Sample Template, you review and pick at it until it is Complete.  
This is your top priority as it will dictate the eventual, 'Employee Benefit Statements Precise data list'.
Section 2 -Data & the Workflow of a Project
Section 1- For HRIS PersonSection 2- Benefit statements Data & the Workflow of a Project
We take data for employee benefit statements in its "Best - Current available form".  This makes life much easier for your HRIS Specialist or IT Team member.
 Employee Benefit Statements Data Requirements
?
Most Vendors for Employee Benefit Statements insist on 'Flat File".  It is unlikely that your HRIS stores employee data in Flat File Tables as it is 'bad design'.  It is usually much easier for you to give us employee files (Tables) as they are on your system.  We create the Joins, which should reduce your time, increase the overall flexibility & 'reuseability' of the employee benefit statements Project. If we begin the employee benefit statements project thoughtfully, you'll be able to rapidly create targeted employee communications at any time in the future.
Comp (General)employee _idemployee _pay_ratewhateverwhateverwhatever
Example123452000############
Table 1 Employee Census (+ or -) depends on the Project & your System
Table 2 Comp (+ or -)
Table 3 Benefits (+ or -)Initially Optional-Later Mandatory
Example below shows 'Starter Tables' for Employee Benefit Statements - Precise data requirements depend on the Project and your Future Plans
Next: Employee Benefit Statements Access
See some Samples