each project has its special circumstances in this is the reason to consider  the project management as a unique job for each project. there is no possibility to repeat the same management technique exactly but you need to investigate the environment of each case. previous work will allow you to have wide experiences to select the suitable action for any case. regarding the consultant variation, it depend mainly on the requirement of project, owner, architecture engineer or other causes, all parties may effect on the variation actions during the project life cycle.

you probably need to give us more information before we can help you directly as this is a huge question.   However here are a few of my own pieces of work in the area that might give you some ideas.

First a book about the way th worlds top architects go about designing.

Lawson, B. R. (1994). Design in Mind. Oxford, Butterworth Architecture.

This book may be out of print now in which case try the following which is an even more general text on the nature of design and uses some of this materials

Lawson, B. R. (2004). What Designers Know. Oxford, Elsevier-Architectural Press.

Lawson, B. R. (2006). How Designers Think. Oxford, Architectural Press (an imprint of Elsevier).

next a paper about how much resources are needed to provide the consultancy design process and what value clients put on it.

Lawson, B. R. and S. Pilling (1996). "The cost and value of design." Architectural Research Quarterly 4(1): 82-89.

finally a paper on the way clients and consultatns learn from one project to another and transfer that knowledge, this might interest you in terms of repeated or not consultant teams.

Lawson, B. R., M. Bassanino, M. Phiri and J. Worthington (2003). "Intentions, practices and aspirations: Understanding learning in design." Design Studies 24(4): 327-339.

Thanks Bryan,I was trying to look the best methodology that can be used to investigate the causes and the impacts of consultant initiated variations in building projects.

I suggest that you collect information from previous projects in your region. You also can take a look at some previous research work.

Thanks Bashar

each project has its special circumstances in this is the reason to consider  the project management as a unique job for each project. there is no possibility to repeat the same management technique exactly but you need to investigate the environment of each case. previous work will allow you to have wide experiences to select the suitable action for any case. regarding the consultant variation, it depend mainly on the requirement of project, owner, architecture engineer or other causes, all parties may effect on the variation actions during the project life cycle.

If it is an exploratory research, then you can go for qualitative research by collecting data through interviews. Preparation for the interviews is achieved by in-depth literature review to touch upon the critical points. Then you analyse your data and report findings. 

Interesting answer Hassan,would you advise to use questionnaires as well to collect data on previously done projects in my area?

General:

Quoted:

The methods by which change can be brought about under a construction contract can be categorised under two broad headings. The first is through provision within the contract terms - examples being JCT05 SBC Section 5 in association with Cls. 3.10 – 3.14 (cl. 2.26 to 2.29 and 4.23 to 4.26 support the change) and ICE 7th cl.51/52. These conditions give the employer's agent (architect/contract administrator/engineer) limited powers to implement change by way of variations. The contractor has no power to authorise change to the works.

The alternative mechanism is through the re-negotiations of the contractual terms, in effect agreeing a new or revised contract. Alternatively the principal parties may agree a separate contract collateral to the existing contract – one which allows for the desired variations. A typical example of such renegotiations would be an agreement to accelerate the works to achieve an earlier than forecast completion date - where no provision existed within the contract for the administrator to instruct acceleration (Refer ACA form cl. 11).

Unquote

Consultant-introduced variations.must fall within the powers granted by the owner to the consultant or must be specifically authorized by the owner. Otherwise may have been given ultra-vires and be voided or may be a cause for damages  from the    owner to the consultant that was acting as an agent for him.

The effects of variations on the contract may be two:  1) Time and 2) Cost

1) Time; a) ask the contractor to make a revised program; b)  make an impact-program to establish the effect of the variation and assess whether there is a critical impact that may increase / decrease the overall contract time in program of works.

2) Cost:  Establish whether there is an increase/decrease on quantities of work and evaluate them (a) on contract rates, (b) on similar rates (c) on reasonable / market rates, in the absence of the first two conditions. Then evaluate the cost of any critical impact on the program, on time related cost basis.

The contractor may be entitled to provide his offer for the additional costs, but this depends on express or implied terms of your contract (you did not say which contract and in which jurisdiction).  Under some contracts / jurisdictions a given percentage of cost increase/decrease may be admitted without requiring a" re-balancing" of the contract,price or without changing the existing rates..

Lastly make sure that the variations are buildable and that not radically changing the contract, or they may frustrate the contract itself.  Consultations between contractor, consultant and the owner, in a spirit of cooperation, fairness (say good faith and technical flexibility (say if some practical adapting is requested), where appropriate) are ultimately essential to establish the consequences of the consultant induced variation deal with them from the contract point of view  and manage their implementation.in practical terms.

If necessary avail of specific consultants (e.g. delay analyst) or a legal counsel.

I hope I have been helped to get inside the subject matter.

Dear Chisanga,

This is an interesting topic that you are working on. I have just heard about variations made by the clients in the construction projects. I think the method that you are looking for depends on how much time you have for your research. Assume that it  is a few month research, you might utilise qualitative method by designing a semi-structured questionnaire or maybe a phone interview. Hope it helps.

Thanks for all your contributions.

My suggestion is to use the KPI´s like: Time, Operation Cost and Throuput