Effects of Inputs from the Preconstruction Activities on the Design Phase of Construction Projects

Success of the design of a project would depend on the adequacy of its inputs.The adequacy of inputs from the preconstruction activities is important to achieve effective delivery of a design and then the construction project. This study focused on identifying the relevant preconstruction activities and analyzing the adequacy of use of the outputs of preconstruction activities as inputs to the design of construction projects. Thirty eight design phase related preconstruction activities were identified through literature review. Data was collected using a structured questionnaire regarding the adequacy of the inputs from the identified preconstruction activities to the design phase from the professionals involved in construction projects in the industry. The data was analysed by multiple regression analysis and using the best fit, a model to predict the Relevance and Adequacy/Inadequacy of outputs of preconstruction activities (as inputs to the design phase) was proposed. Exponantial relationship between Relevance (x) of the preconstruction activity and Adequacy (y) of the output of the of the carried out preconstruction activity (as the input to the design phase)was found as the best fit of the multiple regression analysis in the form of “y = 2.6916e0.024x”. Also, % of Inadequacy (z) = 100% % Adequacy. Hence, a model to predict % Inadequacy,"z = 100% y = 2.6916e0.024x”, was proposed to find out the inadequacy of the use of output of a relevant preconstruction activity.


Introduction
Design shortcomings were identified as the main contributory factor for cost and time overruns of construction projects [1]. Further, design related issues were found among the most problematic factors [2,3] and significant in creating issues in construction projects [4,5]. It was revealed, failure to identify project risks at design stages was seen as a cause for failure in construction projects [6]. It was also stated design errors [5,7], and erroneous design work/processes including attitudes of the designer [6] created issues in construction projects. Poor designs [3,4,7] delay in designs [2,4], design changes [3,4], client driven design changes [4,5,7], and change orders due to design changes [4,5] were identified as contributing to overruns in construction projects.
More time spent during early briefing stage of the design to define the scope and complexity of the project and complete design information leads to more accurate budget estimates of the projects [7]. The following literature highlighted how the effects of design phase contributed to issues in construction projects [8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24].
Proper attention paid at the preconstruction stage [25] and proper preconstruction planning [26] was seen to contribute to the success of construction projects. Based on the above, the objectives of the study were to identify the preconstruction activities of construction projects and to analyze the adequacy of use of the outputs of preconstruction activities as inputs to the design phase of the construction projects. ENGINEER 32 2

Literature Review
Proper attention paid at the preconstruction phase enables the executors of construction projects to carry out professional monitoring and controlling of the two most important aspects of a project, time schedule and the budget more effectively [25]. Also it was observed when preconstruction planning was done, slippage of project schedules and overruns of the project costs could be mitigated to a great extent, if not eliminated [25]. How preconstruction planning affects cost savings and how the preconstruction planning methods promote sustainability and valuable information to investors and owners were highlighted [27]. Preconstruction planning was claimed to be a major determinant for project success [28].
Technological advancement and continuous fragmentation of the construction industry have resulted in a spiral increase in complexity of building projects. The contractors have failed to adjust their planning to more detailed level and the industry still plan the projects at the activity level. Failure to plan projects at role level, like planing for each roleplayer to carry out the activity, is widening the gap between the contractors, subcontractors and the operatives. Hence the approach may need to be replaced by allocation of adequate time during preconstruction planning to enable the main contractors to carefully collaborate with their subcontractors, consultants and suppliers to effectively carry out the preconstruction planning required at this stage of the project [26].
It was stated that preconstruction activities were predominantly analytical and administrative but were especially important since they would set the framework of cost and schedule control of the project. Also preconstruction activities were set into four subsets; 1) job setup 2) purchasing 3) performance model and 4) job startup [29].
A three-step sequential route was identified to carry out preconstruction activities during the planning or pre-design phase: 1) initial concept and scope of the work, 2) professional evaluation of the project-feasibility report and 3) appropriate data-collection [25].
Based on above reviews information and inputs related to the preconstruction phase are listed in Table 1.

Methodology and Data Collection
This study focuses on a real problem in the construction industry. As such, applied research method, a mix between quantitative and qualitative types of research methods together with descriptive methods and analytical research method [30, 31] were used to develop the research methodology.
A structured questionnaire to collect data regarding relevance of the identified preconstruction activities (Table 1) to the projects and their possible effects on the design phase of the project/s was developed. Data on the Relevance and Adequacy of preconstruction activities as inputs to the design phase of construction projects were collected from the respondents using the questionnaire which was tested through a pilot survey. The respondents reported the Relevance and then Adequacy of preconstruction activities in a Likert scale of percentages (as given in the questionnaire). Even though the Likert scale is ordinal, when the scale is symmetric and equidistant it behaves like an interval-level measurement and if well presented it approximates to an interval-level measurement.
The data was collected from different sectors of construction like; building, roads, bridge, water supply, steel construction, from responsible professionals involved in those projects.
Responses were collected from thirty two construction projects for the identified thirty eight preconstruction activities regarding their Relevance and Adequacy to the designphase of the project. Based on the responses, data from those preconstruction activities which were identified as Relevant and 100% Adequate for the projects were used (see Table  2) for the analysis which is described in section 4.

General
Responses received from the questionnaire were verified for clarity from the respondents and analysed to find meaningful relationships between the Relevance of preconstruction activities and Adequacy (or Inadequacy) level of their input to the design phase.

Relationship between Relevance and Adequacy of preconstruction activities
The data highlighted a possible relationship between the responses on Relevance of the preconstruction activities and the Adequacy of use of the outputs of preconstruction activities as inputs to the design of the construction projects. A model to predict the relationship between relevance and adequacy (or inadequacy) of preconstruction activities would be useful during the design phase to gauge the contribution of the preconstruction activities.

Deriving the appropriate relationship between relevance and 100% adequacy for a preconstruction activity as an input to the design
When a preconstruction activity is relevant for a construction project, it appears the output of the activity (as the input) to the design phase has to be adequate to satisfy the purpose of an effective design. Hence finding a relationship between the two, relevance and adequacy (as explained) is done as given below.
Line fitting was utilized to test the relationship between relevance of the preconstruction activities and adequacy of the outputs of preconstruction activities as inputs to the design of the construction projects. Using regression analysis, the most appropriate relationship was determined as the exponential relationship between the variables Relevance and Addequacy, as it had the highest coefficient of determination, R 2 (=0.4), being the closest to the perfect fit (=1.0). Table  3 below gives details of gives the possible types of relationships arrived using regression analysis). Accordingly the exponential relationship between the variable 'Relevance' and dependent variable 'Adequacy' was found to be the most appropriate relationship. y = 2.6916e 0.024x …….... (1) When a designer needs to estimate the adequacy of the outcome of a preconstruction activity as input to the design he can use the model given by equation (1). For example, consider the preconstruction activity, 'Geotechnical Survey', which is 100% relevant to the project. Using equation (1) the adequacy of the preconstruction activity 'Geotechnical Survey', y= 2.6916e 0.024x100 = 30%. Also, % Inadequacy (z) = 100%-% Adequacy(y). i.e. % of Inadequacy (z) = 100%-2.6916e 0.024x = 70% Figure 1 was derived using, equation (1), the most appropriate relationship for Relevance and Inadequacy, z = 100% -2.6916e 0.024x as discussed above. Using the model in Figure 1, when the relevance of an activity is known, appropriate inadequacy level of the input for the design can be found. With the above finding the options available for the designer are; i.Improve the reliability of available data for the preconstruction activity to decrease/eliminate Inadequacy level of the activity by obtaining additional data(say data from further boreholes) before commencing the design.
ii.Designer opts for a judgement based on his knowledge, experience, exposure etc. and continues with the design, irrespective of the 70% inadequate value derived from the model. When a designer needs to estimate the adequacyof theoutcome of a preconstruction activityas input to the design he can use the model given by equation (1). For example, consider the preconstruction activity, 'Geotechnical Survey', which is 100% relevant to the project. Using equation (1) the adequacy of the preconstruction activity 'Geotechnical Survey', y= 2.6916e 0.024x100 = 30%. Also, % Inadequacy (z) = 100%-%Adequacy(y).
i.e. % of Inadequacy (z) = 100%-2.6916e 0.024x = 70% Figure 1 was derived using, equation (1), the most appropriate relationship for Relevance and Inadequacy, z = 100% -2.6916e 0.024x as discussed above. Using the model in Figure 1, when the relevance of an activity is known, appropriate inadequacy level of the input for the design can be found. With the above finding the options available for the designer are; i.Improvethe reliability of available data for the preconstruction activity to decrease/eliminate Inadequacy level of the activity by obtaining additional data(say data from further boreholes)beforecommencing the design.
ii.Designer optsfor a judgement based on his knowledge, experience, exposure etc. and continueswith the design, irrespective of the 70% inadequate value derived from the model.
If option i) was considered for the design, to rectify the identified faults, the designer would have to improve the input of the data of the activity. This would result in possible overruns in time (time the design team used in working on option ii), possible delay in construction (as a practice construction follows design until the design is rectified) and increase in costs (possible costs due to variations in a construction activity / activities).

Possible errors could surface;
a) During the design phase before issuing drawings for the construction phase. b) After construction drawings were issued and design faults were identified during the construction phase. c) During operational phase of the project.
If option ii) was taken by the designer, and it resulted in an effective design, then there would be no issue. Such a decision would depend significantly on the knowledge, experience, exposure, etc. of the designer. When a designer needs to estimate the adequacyof theoutcome of a preconstruction activityas input to the design he can use the model given by equation (1). For example, consider the preconstruction activity, 'Geotechnical Survey', which is 100% relevant to the project. Using equation (1) the adequacy of the preconstruction activity 'Geotechnical Survey', y= 2.6916e 0.024x100 = 30%. Also, % Inadequacy (z) = 100%-%Adequacy(y).
i.e. % of Inadequacy (z) = 100%-2.6916e 0.024x = 70% Figure 1 was derived using, equation (1), the most appropriate relationship for Relevance and Inadequacy, z = 100% -2.6916e 0.024x as discussed above. Using the model in Figure 1, when the relevance of an activity is known, appropriate inadequacy level of the input for the design can be found. With the above finding the options available for the designer are; i.Improvethe reliability of available data for the preconstruction activity to decrease/eliminate Inadequacy level of the activity by obtaining additional data(say data from further boreholes)beforecommencing the design.
ii.Designer optsfor a judgement based on his knowledge, experience, exposure etc. and continueswith the design, irrespective of the 70% inadequate value derived from the model.
If option i) was considered for the design, to rectify the identified faults, the designer would have to improve the input of the data of the activity. This would result in possible overruns in time (time the design team used in working on option ii), possible delay in construction (as a practice construction follows design until the design is rectified) and increase in costs (possible costs due to variations in a construction activity / activities).

Possible errors could surface;
a) During the design phase before issuing drawings for the construction phase. b) After construction drawings were issued and design faults were identified during the construction phase. c) During operational phase of the project.
If option ii) was taken by the designer, and it resulted in an effective design, then there would be no issue. Such a decision would depend significantly on the knowledge, experience, exposure, etc. of the designer. 1. List of preconstruction activities identified and used in the study could be a subset of the possible comprehensive list of preconstruction activities that are required during the design phase. 2. The responses received from experts, based on the questionnaire survey, was limited to the professionals from the construction industry in Sri Lanka. Hence, the applicability of the results may be limited to use in the Sri Lankan construction industry.

Further research
This study focused on the 100% adequacy of the inputs of the analysis of the relevant preconstruction activities for the design phase. Hence it could be possible to carryout further research on the preconstruction activities with adequacy of inputs of the analysis is less than 100%. It is also observed that there is room for improvements on the proposed model which gives a relationship between the Relevance andInadequacy of the inputs to the design phase by further research, for example, exploring of the limitations of this study.

Conclusions
Following conclusions are drawn from the study.
 Thirty eight preconstruction activities were identified from the literature review, as relevant inputs to the design phase of the construction projects. These thirty eight preconstruction activities could possibly be a subset of a number of preconstruction activities applicable to the construction industry.
 Based on the responses of the projects considered adequacy levels of the relevant inputs to the design by the outputs of the preconstruction activities were, highest at 44%, average at 23% and the lowest at 3%. Above reflects that none of the inputs from preconstruction activities hasnot even reached an adequacy level of 50%.