The influence of schematic design document on outcome of design and build project of public buildings

. Observing the advantages of integrated solutions for public buildings, the government has accommodated the use of integrated methods through the Minister of PUPR Regulation No. 25 of 2020. The current phenomenon, the minimal initial design is still considered a major weakness. For this reason, it is necessary to explore the level of influence of the schematic design document on the success of the outcome. This research objective was to analyse the influence of the schematic design document on the success of the outcome based on the time variable. The selection of case studies is aimed at public buildings since there are still weak points in the smoothness of the articulation of schematic design documents from service users to design development by service providers. This research approach focuses on intensive and in-depth analysis through observation of project case studies in 3 cities and statistical tests. The results of this exploration indicate that the schematic design document influences the success of receiving the outcome, with the highest influence coefficient of 4.244 on the variable of landscape documents. Hopefully, this study can serve as a performance tool for service user requirements for construction service actors with the Integrated Design and Build Method.


Introduction
Modernization of the construction service sector in increasing competitiveness requires efficient, effective performance through integrated solutions [1][2][3].Observing the advantages of integrated solutions for public buildings, the Indonesian government has accommodated the use of methods such as those contained in PUPR Ministerial Regulation No. 25 of 2020 [4] concerning the procurement of goods and services that are integrated with design.
In more detail, PUPR Ministerial Regulation No. 25 of 2020, in article 10 paragraph 1 point f and article 7 point 1.f.regarding the schematic design document in its implementation the elaboration of the terms of service users has not answered the intention of adequacy of design information in the schematic design document.
The current phenomenon, the minimal initial design is still considered a major weakness.So that it raises skepticism that this design and build method cannot work well for building construction in the public sector.To fill the regulatory gap from the lack of adequate information in the schematic design documents, it is necessary to explore the degree of influence of the schematic design documents on the success of the outcome and what happens to the insufficient information from the schematic design documents.
The purpose of this study was to analyze the role and influence of the schematic design document in the Integrated Design and Build Method on the success of *Corresponding author: ika.bali@president.ac.id the performance or outcome of the building based on the time variable.
The limitation of this research is that the research object consists of 3 construction projects that use integrated design and build methods, especially in the public sector.The selection of case studies is aimed at public buildings because there are still weak points in the smooth delivery of schematic design documents from service users to design development by service providers.

Literature review 2.1 Schematic design
Based on the criteria for design service users in PUPR Ministerial Regulation No. 25 of 2020, in article 10 paragraph 1 point f, regarding initial design (basic design) and article 7 point 1.f.regarding schematic documents, explorations and proposals for completeness of schematic design documents focusing on materials that can bridge the transformation of information from service users to service providers in order to achieve optimal performance.
Regarding PUPR Ministerial Regulation No. 25 of 2020, article 7, point 1f, schematic design documents consist of basic drawings, schematic drawings, cut-out drawings, typical drawings, or other drawings that support the scope of work.The theoretical basis for the details of each building design process in the schematic design stage based on American Institute of Architect [5] is early stage in the design process and the scope is general.While the theoretical basis for schematic design in the guidebook/red book of the Indonesian Institute of Architects [6] is as shown in Table 1.

Table 1. Schematic design stage.
The role of the schematic design document, referring to PUPR Ministerial Regulation No. 25 of 2020 article 10 paragraph 1 concerning service user provision documents, it can be seen the importance of the schematic design document as the basis for preparing/creating budget ceilings, preparing development time plans, determining scope and performance of work, arranging permits.
In a construction project, drawings are the main tool in communicating the parties.In Fig. 1 it can be seen that at each stage of the project construction process [7], it is necessary to document the schematic design document so that: The initiation stage must prepare the drawing document which is a translation of the expectations, goals, and intentions of the service user.
In the next stage, the design development stage, in its development it is necessary to have an initial drawing document that already contains the hopes, goals, and intentions of service users in the construction of this project.At the execution stage, drawing documents are indispensable as a basis for executing work in the field.
At the monitoring and control stage, drawing documents are again needed as a basis for assessment and decision making.
In closing, when handing over a construction project, it is still necessary to document drawings of what has been carried out in the project which will be useful later for maintenance or if an additional function or building area is needed.

Integrated design and build method
Design and Build is all work related to the construction of a building, the provider of which has a single unit of responsibility for the design and implementation of construction.The Integrated Design and Build method, is a development construction contract [8][9], where the design and construction implementation become a single responsibility of the service provider.This idea was born as a fast-track construction approach and the transfer of responsibility is considered the best choice in a development process.The advantages of using the integrated design method [10][11] as follows.First, from a risk management perspective, the synergy of contractors who have field construction expertise during the design process, produces the best field methods and material selection, can minimize errors in the implementation of construction/field work and maximize work results, namely, quality, cost, and time.
An integrated solution, where service users only need to negotiate at one source and make all decisions through one door.Linkages between designers and implementers in a single unit of responsibility can minimize dispute because coordination can run more integrated.The one-door concept facilitates all process changes, feedback, construction issues, payments.
By bringing together, design experts from several divisions and construction experts, provide guarantees, minimize design errors, and better work results.It is hoped that interdisciplinary coordination will result in better results.In determining cost targets, cost monitoring can be done from the design process stage.The integrated engineering method allows early identification of cost, quality, time, and warranty issues to be built.
Second, in terms of efficiency, it only requires a slender organization of service users, and this is very useful for service users in the non-construction sector.

Schematic Design
Based on the approved concept design, architect will develop architectural block design composition and embodied in the drawing.
To assist understanding and suitability for user expectation, goals and purposes of design development.
Information obtained stage for estimated building area, estimated budget, outline material specification, construction system and construction duration.
To assist understanding and suitability for user expectation, goals and purposes of project development.
Design with comply to pattern and design -form, optimal duration and cost.

Design according to local regulations
By carrying out design development responsibilities within the scope of the contractor, project duration can be reduced.Carry out design development work and simultaneously carry out substructure work (assuming permits have been completed).Third, in terms of effectiveness, the success of the integrated engineering method contracting system lies in the flexibility in project management, the combination of cost control and completion time, fast track construction, method, and quality.There is a synergy of the expertise of the designers and the building expertise of the contractors, and enables innovation and value engineering at design time.Also, the procurement period runs shorter and is parallel.
Then, important things that need to be considered from the integrated design method are as follows.First, approaches to consider understanding the needs of service or project users, understanding the risk tolerance of service users, understanding various risk profile approaches, advantages and disadvantages of service providers, the importance of coordination from all parties, cost savings are possible due to the contractor's expertise in materials and work methods, and prepare typical procurement process guidelines.
Second, continuing conflict of interest, generally for design consultants.Architects must follow the development process carefully to ensure the design work is as expected.
Third, integrated engineering methods can reduce claims and litigation.Service users must properly prepare establishment initial information at the design concept stage as information to service providers, schematic design document, performance parameters and expected results, and limit claims.
Fourth, weaknesses of the integrated design method are projects that have many specialties and are exoteric (only a small group can work on), such as a research hospital, and projects that have the potential to change during construction.
In process implementation of Integrated Design and Build contracts, just like the construction process in general, the process and implementation of an integrated design and build contract begins with preparatory work at the initiation stage followed by the preparation of design documents.After that, the stages of design, execution, supervision and monitoring, and closure are carried out respectively as shown in Fig. 2.

Research method
The method used in this study is an in-depth case study approach, with the hope that the complexity of a case can be properly captured.From this case study, verification will be carried out through testing the results of the final work and statistical tests from the case study project using the Integrated Design and Build Method.
The existence of this case study is expected to be able to get a systemic research process to explore research that attracts attention and is reviewed from various points of view in a complete, thorough, and then for intensive analysis of various detailed findings on the object of the case study.While research instruments obtained through: Observations on the construction of 3 public projects.
Interviews with construction workers and discussions with experts.
From points 1 and 2 produce a complete list of design intentions required from the 6 divisions in the schematic design document.Expert test, with a background of practitioners and academics.The test is carried out on the complete list of schematic design documents that have been prepared as information in point 3.
Distributing questionnaires to respondents of construction service providers.The questionnaire is based on tabulated data that has been validated by experts.
The questionnaire submitted relates to the design plans that will be made by each of the following divisions: Architecture division: designing patterns and compositions of architectural forms embodied in drawings in accordance with the provisions.The architect also made a diagram to describe the functional value of the building.
Interior division, designing the layout plan and the beauty of the interior space.Structure division, designing the strength and reliability of buildings according to existing regulations.Mechanical-Electrical-Plumbing (MEP) division, designing building operational performance according to existing needs and conditions.Landscape division, designing the needs and beauty of outdoor space.Green Building division, designing buildings that prioritize energy efficiency and sustainability.
The results of collecting and deepening literature data, in-depth case studies, and the results of discussions with experts obtained at least 50 items of information adequacy needs in the schematic design documents.The intensity of this information to strengthen the design clarity communication tools.

Results and discussion
The results of a literature review and observation of case study objects on the main points of the research problem by measuring the level of influence of schematic design documents, it can be seen that the influence of schematic design documents is very high on other points, such as basic documents for preparing cost calculations, project schedules and duration, list of results expected, the qualifications and number of experts, and the basis for submitting permits (Table 2).
Analysis of the role and influence of schematic design documents through direct observation of case study projects, the results of mitigating the information adequacy of the resulting schematic design documents are shown in Table 3.
From the information adequacy, it was successfully arranged as a forming independent variable (X), which consisted of information adequacy from design intentions and the dependent variable (Y), namely the success of receiving the final results [6,12,13].Expert test results indicate the intensity of information from each work division.The results of the mitigation obtained information needs as shown in Table 4.
For statistical tests, respondent data by occupation and expertise as seen in Fig. 3 and by position and experience as shown in Fig. 4.
Questionnaire tabulation and expert test validation from each division as well as independent variable points (X) which have a correlation with the dependent variable (Y) or the success of receiving the final results or outcomes as shown in Table 5-10.
In the validity test, testing the validity or invalidity of the results of the questionnaire distribution through the Pearson correlation method which connects the correlation of the x variable with the y variable.The number of respondents used was 34 people.The results of the analysis of all indicators turned out to have r count greater than r table of 0.339, which can be concluded that all indicators in this study can be declared valid.Reliability test through consistency, stability, and reliability.If the alpha is low or < 0.5, the questionnaire answers are considered unreliable.Of the intended number of respondents, it can be trusted to understand well the questionnaire given.The results of the reliability test with a Cronbach's alpha value of 0.961 > 0.6, it can be concluded that 51 variables are valid (50 variables x and 1 variable y) and are included in the high reliability category.
Correlation test to find the strength of the degree of connection or correlation between the schematic design document variable (x) and the final result acceptance variable (y).Based on the results of the correlation test, of the 50 independent variables (x) there are 21 variables that have a relationship with the final success variable (y).
Regression analysis is a study of the dependence of one variable on one or more other variables and the magnitude of the influence of the variables (x) on the schematic document design variable (y) on the acceptance of the final result.Although the analysis deals with dependency, it does not necessarily imply causation.The results of the regression model using the stepwise method are shown in Table 11.
The results of Table 11 show that the number of regressions formed is 4 (four) models.
The variables forming the model I are combined by the X43 variable.The R 2 value is 0.770 while the model forming variable is 0.770.Which means that the variable X43 is a variable that forms model I which can contribute to a change in Y of 77.0%.The variables forming the model II are combined by the variables X43 and X26.The R 2 value obtained from the model forming variables is 0.931.The difference in the value of R 2 (R Square Change) for models I and II is 0.161.Which means X26 in the model forming variable II can contribute to a change in Y of 16.1%.
The variables forming the model III are combined by the variables X43, X26 and X34.The R 2 value obtained from the model forming variables is 0.945.The difference in the R 2 values for the model forming variables II and III is 0.014.Which means that at X34, the variables forming model III contributed to a change in Y of 1.4%.
The variables forming the IV model are combined with the variables X43, X26, X34, and X1.The R 2 value obtained from the model forming variables is 0.957.The difference in the R 2 value of the variables forming models III and IV is 0.012.Which means that X1 in the model forming variable IV contributes to a change in Y of 1.2%.
The model test is a follow-up step from the Stepwise method, after the linear model is obtained, then a model test is carried out in the form of the F test.The F test is a simultaneous test to determine the relationship or effect of the independent variable (x) simultaneously on the dependent variable (y).The obtained F table is 2.40 (Table 12).Thus, that X43, X26, X34 and X1 as part of the information completeness of the schematic design document has a significant effect on the acceptance or performance of the outcome.Where X43 is the highest influence coefficient of 4.244 on the variable of landscape documents.

Conclusion
Based on the analyzed results of this study it can be concluded, the schematic design document influences the acceptance of the outcome and plays a role in minimizing the risk of failure in the next stage.
This conclusion is supported by the results of statistical tests as follows.Of the 50 independent variables (x) of the schematic design documents, there are 21 variables that have a correlation with the dependent variable (y) acceptance of the outcome.The 21 variables consist of architectural division (8), interior (4), structure (5), MEP (1), landscape (2) and green building (1).
There are 4 variables (x) which have a very big influence on (y), namely: X43, X34, X26, and X1.Where X43 is a variable related to making special notes on landscape documents that are referenced with design intentions; X34 related to the MEP Design Schematic document in the form of a worksheet calculation of MEP work to ensure building operational performance; X26 related to the idea of planning and designing the substructure in the form of drawings and calculations of the types of foundations, pile caps, tie beams that have met the provisions for bearing capacity, strength and earthquake resistance according to SNI and national and local regulations; and X1 related to the architectural schematic design document containing planning and design ideas From the results of the t test, the four independent variables (x) on t table have a dominant influence coefficient value: X43 is 4.244, X34 is 3.218, X26 is 3.393, and X1 is 2.909.Where X43 as part of the information completeness of the schematic design document has a highest significant effect on the acceptance of the outcome.

Table 2 .
Level of influence of the schematic design document.

Table 3 .
Role and influence of the Schematic Design document of each division.

Table 4 .
The information intensity of each work divition.

Table 5 .
Variables of architecture division.

Table 6 .
Variables of interior division.

Table 7 .
Variables of structure division.

Table 8 .
Variables of MEP division.From the analysis of Table12it can be concluded that the test results are 163.257> 2.40 and simultaneously the independent variable (x) the schematic design document affects the dependent variable (y) the acceptance of the final result.The results of this analysis show that the completeness of the schematic design document influences the success of the final result performance.

Table 9 .
Variables of landscape division.

Table 10 .
Variables of green building division.

Table 12 .
Results of test F.

Table 13
shows the analysis of the results of the t test using SPSS, the results of the t test are obtained as follows.X43 (Making special notes on landscape documents with reference to design intentions), with t count 4.244 > 2.05813.

Table 13 .
Results of test t.X26 (It contains ideas for planning and designing the substructure in the form of drawings and calculations of the types of foundations, pile caps, tie beams that have met the requirements for bearing capacity, strength, and earthquake resistance according to SNI and national and local regulations), with t count 3.393 > 2.05813.X34 (MEP schematic design document in the form of a worksheet calculation of MEP work to ensure building operational performance), with t count 3.218 > 2.05813.X1 (Architectural schematic design document contains planning and design ideas), with t count 2.909 > 2.05813.