Dear Sher Ullah,
Please do understand the phases which are involved during OBIA/OBIEE implementation:
1. We need to do OBIA hardware sizing which include Database, ETL, and BI Server configuration based on volume of data and number of users. Here you may have to pitch in with BI Architect.
2. We need to install Informatica Server & Client, DAC Server & Client, and OBIEE Server & Client for creating the infrastructure for OBIA. Here you have to pitch in with BI Consultant with right kind of skill.
3. We need to configure the modules of OBIA. Here again you have to pitch in with BI Consultant with right kind of skill.
4. For customizing and finalizing the business requirements we need to pitch in with BI Functional Consultant.
5. Definitely PM is required for smoothly running the project.
Going into more details now question arise,
Can we live without Functional resource for pre-built Solution of BI Apps? Does a technical person can also explain Finance and HRMS dashboards.. ?
Answer is at any case i will have a EBS/domain Functional Consultant who shall be very useful in identifying the COA, Organization Hierarchies, lookups including SITs and EITs. EITs are important and shall most of the time will result in customization in OBIA HRMS and so forth for other modules. You need to also know to what extend the source system is customized and factor that to customize the target Informatica/ODI mappings. I am not sure which one you are choosing.
Believing technical resource can address business questions is a sure receipie for BI failed projects.For example in case of OBIA The OOTB will not produce p and l plus Balance sheet correctly and shall require customization especially if they are not US based. This means you still need to rely on Functional Expertise. I have seen during implementation stages when the client asked where are my specific hierarchies, technical persons does not have clue of what they are!
Further adding to your question there is also requirement to have more then Functional and technical consultants.
Following can be a road map of implementation which also tell which resource required.
1. Start with Functional Consultant and PM for gathering requirements, understanding the source system customizations, and understanding the reports which Client is already using.
2. Simultaneously pitch in with BI Architect for OBIA hardware sizing which include Database, ETL, and BI Server configuration based on volume of data and number of users.
3. BI Architect can again help in finalizing the customized reports which can be delivered and which cannot be delivered.
5. Finalize the reporting requirement.
6. Start setting up OBIA infrastructure and OOTB configuration (BI Consultants).
7. Based on customized requirement and volume of work pitch in with ETL and Analytics resource (BI Consultants).
8. Testing phase will require passing few real time transactions on Souce System in DEV environment and then verifying the outputs. Your Functional Consultant can do this with the help of BI Consultant.
Please let me know if you need more help.