Project Manager as a Business Analyst

Project Manager and Business Analyst roles both require unique skillsets and are definitely unique specializations. The well balanced combination of the two is a key contributor towards any project success.
Sometimes there is a need for the same person to assume both the roles. When Project Managers assume the role of a Business Analyst (One of the reasons for this may be a small budget project), there are a lot of factors that come into play due to this.
In all these years working in the Insurance IT Industry, i have seen numerous Projects suffer when the role to person matching is not perfect.
Reasons:
As mentioned above some projects may or may not have the luxury of a separate role for a Business Analyst. This may be due to varying reasons based on,
1> Overall Project scope
2> Project Budget allocated
3> Available resource knowledge base
4> Most importantly, no clear understanding of the difference between these 2 roles by the stakeholders and sponsors

When the Project Manager assumes the role of a Business Analyst, there are some things he has to keep in mind to ensure success in the role. This BA role essentially fits quite snugly in the Project Manager's domain due to the fact that both the roles require managing client expectations and having clear and concise client interactions. One role is focused towards successfully gathering project business requirements (Business Analyst) and the other geared towards entire project success (Project Manager).

Common factors:
The skillsets that are common for both Project Management and Business analysis are,
1> First and foremost is Communication skills
2> Understanding the entire the project lifecycle
3> Strong Stakeholder Management skills

Specific skills:
Skillsets that are specific to the Business Analyst role are,
1> Strong business process background
2> Understanding of Business analysis as a work function wrt gathering, analyzing and documenting requirements
3> Understanding people management wrt Business Analysis
Certain things to be kept in mind by the project manager when assuming the role of a Business analyst.
Success Factors:
 1> Being completely aware of the business processes
    For the Project Manager to be successful as a Business Analyst, he has to understand the business overall, the business process flow, the business value chain. Without the knowledge of these process areas, the Project Manager will not be able to meet the expectations for the BA role.
    You usually acquire this knowledge by working for a number of years in the Industry.
    For example: In my case, being in the Insurance IT domain, interacting with Business people for over 12 years now, gives exposure to all areas of Insurance business processes like Policy, Billing and Claims etc.
    Along with this, having a Project Management exposure is a definite plus, as it gives you the overall 360 degree view of the entire project gamut and thus helps streamline your thinking process.
   
2> Complete awareness of the Stakeholders expectations from the project.
   Since both project Manager and BA role both deal with stakeholders, there is a big difference between the 2 roles. One role is more concerned with the overall Project success by meeting stakeholder expectations (PM role), whereas the other role (BA) is more concerned with the business process expectations that must be fulfilled on completion of the project.
   You have to be constantly interacting with the Stakeholders so that you understand their expectations, pain points etc
  
3> Ensure the Business SMEs and End Users are aligned and aware of the project goals and objectives, the high level executive direction outlined for the project.
   As mentioned above, since business stakeholders, Subject Matter Experts, End Users may be aware of a specific area of project objective (i.e. Project will help in enhancing and executing XYZ business process in a shorter time frame and efficient manner), but it helps them to be aware of overall project objectives (e.g. Project will help achieve XYZ functionality more efficiently based on the requirements gathered in next 2 weeks and developed over the next 6 weeks duration for a certain cost and resource outlined)
  
4> Project Business documentation expectations
   Project Manager may be aware of the overall Business Analyst Role expectations from the delivery perspective, he has to be able to create Functional requirements documents, Gap documents, Use cases, UI specifications etc documentation as the case may be.
  
5> Help Quality and Testing Team in their analysis and Q&A
   Business Analyst along with the business stakeholders also has to be cognizant of the other members playing specific roles attributing to project success e.g. Quality Analysis Team, Process Management Team, Testing and infrastructure Teams.
Also last but not the least, Business analysts have to be somewhat of a Techo functional experts meaning along with understanding the Business aspects of the project, they also have to understand the technical dependencies, implications, risks posed by certain requirements and thereby come up with possible solutions alternatives. Business analysts are essentially bridges between the End business users and development Teams. They understand and gather the business requirements and translate and transform them to Specifications, use cases and functional requirement documentations which will make it easy for the technical developers to follow and design and code accordingly. These documentation will then also be used by the Testing and Quality Team so they can base their Test Cases and Test scenarios off them.

So in essence, Project Manager is more concerned or related to the big picture and the totality to complete the project, while a Business Analyst is more closer to the requirement understanding, gathering and documenting tasks.  Both the roles have certain commonalities and some differences, but it certainly helps in the project success, if the 2 roles have a good background of the other role and its expectations.
If the same person fill in for both the roles, the necessary and required skillset to guarantee the project success would be balanced combination of Project Management, Business knowledge, Technical background of the development platform used etc.