Key Software Metrics and its Impact on each other for Software Development Projects

Every software development project is unique and different from repeatable manufacturing process. Each software project share different challenges related to technology, people and timelines. If every project is unique, how project manager can estimate project in a consistent way by applying his past experience. One of the major challenges faced by the project manager is to identify the key software metrics to control and monitor the project execution. Each software development project may be unique but share some common metric that can be used to control and monitor the project execution. These metrics are software size, effort, project duration and productivity. These metrics tells project manager about what to deliver (size), how it was delivered in past (productivity) and how long will it take to deliver with current team capability (time and effort). In this paper, we explain the relationship among these key metrics and how they statistically impact each other. These relationships have been derived based on the data published in book “Practical Software Estimation” by International Software Benchmarking Group. This paper also explains how these metrics can be used in predicting the total number of defects. Study suggests that out of the four key software metrics software size significantly impact the other three metrics (project effort, duration and productivity). Productivity does not significantly depend on the software size but it represents the nonlinear relationship with software size and maximum team size, hence, it is recommended not to have a very big team size as it might impact the overall productivity. Total project duration only depends on the software size and it does not depend on the maximum team size. It implies that we cannot reduce project duration by increasing the team size. This fact is contrary to the perception that we can reduce the project duration by increasing the project team size. We can conclude that software size is the important metrics and a significant effort must be put during project initiation phases to estimate the project size. As software size will help in estimating the project duration and project efforts so error in estimating the software size will have significant impact on the accuracy of project duration and effort. All these key metrics must be re-calibrated during the project development life cycle.

How software size influence productivity and project duration

To make a perfect project plan, the software size of the order from the customer is the most important factor. The biggest challenge for the project manager is to estimate the project end date in the beginning of the project i.e. in project planning phase with realistic accuracy. Apart from other major inputs to estimate the project end date, expected team capability (productivity) and estimated software size are the major inputs that may influence the project end date. Software size is one of the most significant independent metric available in the planning phase and project manager has to estimate the other metrics based on the initial estimated software size. There is no direct relationship available between software size and project duration or software size and team productivity, however, there are industry data published by Quantitative Software Management and ISBSG that shows how these metrics influence each other. In this paper, using the data published by ISBSG and Quantitative Software Management, we try to statistically establish how productivity and project duration are influenced by software size. We have done linear regression analysis by generating the secondary data based on the data published by ISBSG and Quantitative Software Management. Linear regression equation validated with the actual project data and experimental results suggest that that productivity is significantly dependent on software size, however, project duration does not significantly depend on software size but may also be dependent on other metrics like team size, apart from software size

Autoinflation for otitis media with effusion (OME) in children

BACKGROUND: Otitis media with effusion (OME) is an accumulation of fluid in the middle ear cavity, common amongst young children. The fluid may cause hearing loss. When persistent, it may lead to behavioural problems and a delay in expressive language skills. Management of OME includes watchful waiting, medical, surgical and mechanical treatment. Autoinflation is a self-administered technique, which aims to ventilate the middle ear and encourage middle ear fluid clearance by providing a positive pressure of air in the nose and nasopharynx (using a nasal balloon or other handheld device). This positive pressure (sometimes combined with simultaneous swallow) encourages opening of the Eustachian tube and may help ventilate the middle ear. OBJECTIVES: To assess the efficacy (benefits and harms) of autoinflation for the treatment of otitis media with effusion in children. SEARCH METHODS: The Cochrane ENT Information Specialist searched the Cochrane ENT Register; Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE; Ovid Embase; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials. The date of the search was 20 January 2023. SELECTION CRITERIA: We included randomised controlled trials (RCTs) and quasi-randomised trials in children aged 6 months to 12 years with unilateral or bilateral OME. We included studies that compared autoinflation with either watchful waiting (no treatment), non-surgical treatment or ventilation tubes. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcomes were determined following a multi-stakeholder prioritisation exercise and were: 1) hearing, 2) OME-specific quality of life and 3) pain and distress. Secondary outcomes were: 1) persistence of OME, 2) other adverse effects (including eardrum perforation), 3) compliance or adherence to treatment, 4) receptive language skills, 5) speech development, 6) cognitive development, 7) psychosocial skills, 8) listening skills, 9) generic health-related quality of life, 10) parental stress, 11) vestibular function and 12) episodes of acute otitis media. We used GRADE to assess the certainty of evidence for each outcome. Although we included all measures of hearing assessment, the proportion of children who returned to normal hearing was our preferred method to assess hearing, due to challenges in interpreting the results of mean hearing thresholds. MAIN RESULTS: We identified 11 completed studies that met our inclusion criteria (1036 participants). The majority of studies included children aged between 3 and 11 years. Most were carried out in Europe or North America, and they were conducted in both hospital and community settings. All compared autoinflation (using a variety of different methods and devices) to no treatment. Most studies required children to carry out autoinflation two to three times per day, for between 2 and 12 weeks. The outcomes were predominantly assessed just after the treatment phase had been completed. Here we report the effects at the longest follow-up for our main outcome measures. Return to normal hearing The evidence was very uncertain regarding the effect of autoinflation on the return to normal hearing. The longest duration of follow-up was 11 weeks. At this time point, the risk ratio was 2.67 in favour of autoinflation (95% confidence interval (CI) 1.73 to 4.12; 85% versus 32%; number needed to treat to benefit (NNTB) 2; 1 study, 94 participants), but the certainty of the evidence was very low. Disease-specific quality of life Autoinflation may result in a moderate improvement in quality of life (related to otitis media) after short-term follow-up. One study assessed quality of life using the Otitis Media Questionnaire-14 (OMQ-14) at three months of follow-up. Results were reported as the number of standard deviations above or below zero difference, with a range from -3 (better) to +3 (worse). The mean difference was -0.42 lower (better) for those who received autoinflation (95% CI -0.62 to -0.22; 1 study, 247 participants; low-certainty evidence; the authors report a change of 0.3 as clinically meaningful). Pain and distress caused by the procedure Autoinflation may result in an increased risk of ear pain, but the evidence was very uncertain. One study assessed this outcome, and identified a risk ratio of 3.50 for otalgia in those who received autoinflation, although the overall occurrence of pain was low (95% CI 0.74 to 16.59; 4.4% versus 1.3%; number needed to treat to harm (NNTH) 32; 1 study, 320 participants; very low-certainty evidence). Persistence of OME The evidence suggests that autoinflation may slightly reduce the persistence of OME at three months. Four studies were included, and the risk ratio for persistence of OME was 0.88 for those receiving autoinflation (95% CI 0.80 to 0.97; 4 studies, 483 participants; absolute reduction of 89 people per 1000 with persistent OME; NNTB 12; low-certainty evidence). AUTHORS' CONCLUSIONS: All the evidence we identified was of low or very low certainty, meaning that we have little confidence in the estimated effects. However, the data suggest that autoinflation may have a beneficial effect on OME-specific quality of life and persistence of OME in the short term, but the effect is uncertain for return to normal hearing and adverse effects. The potential benefits should be weighed against the inconvenience of regularly carrying out autoinflation, and the possible risk of ear pain

Antibiotics for otitis media with effusion (OME) in children

BACKGROUND: Otitis media with effusion (OME) is an accumulation of fluid in the middle ear cavity, common amongst young children. The fluid may cause hearing loss. When persistent, it may lead to developmental delay, social difficulty and poor quality of life. Management of OME includes watchful waiting, autoinflation, medical and surgical treatment. Antibiotics are sometimes used to treat any bacteria present in the effusion, or associated biofilms. OBJECTIVES: To assess the effects (benefits and harms) of oral antibiotics for otitis media with effusion (OME) in children. SEARCH METHODS: The Cochrane ENT Information Specialist searched the Cochrane ENT Register, CENTRAL, Ovid MEDLINE, Ovid Embase, Web of Science, ClinicalTrials.gov, ICTRP and additional sources for published and unpublished studies to 20 January 2023. SELECTION CRITERIA: We included randomised controlled trials and quasi-randomised trials in children aged 6 months to 12 years with unilateral or bilateral OME. We included studies that compared oral antibiotics with either placebo or no treatment. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcomes were determined following a multi-stakeholder prioritisation exercise and were: 1) hearing, 2) otitis media-specific quality of life and 3) anaphylaxis. Secondary outcomes were: 1) persistence of OME, 2) adverse effects, 3) receptive language skills, 4) speech development, 5) cognitive development, 6) psychosocial skills, 7) listening skills, 8) generic health-related quality of life, 9) parental stress, 10) vestibular function and 11) episodes of acute otitis media. We used GRADE to assess the certainty of evidence for each outcome. Although we included all measures of hearing assessment, the proportion of children who returned to normal hearing was our preferred method to assess hearing, due to challenges in interpreting the results of mean hearing thresholds. MAIN RESULTS: We identified 19 completed studies that met our inclusion criteria (2581 participants). They assessed a variety of oral antibiotics (including penicillins, cephalosporins, macrolides and trimethoprim), with most studies using a 10- to 14-day treatment course. We had some concerns about the risk of bias in all studies included in this review. Here we report our primary outcomes and main secondary outcome, at the longest reported follow-up time. Antibiotics versus placebo We included 11 studies for this comparison, but none reported all of our outcomes of interest and limited meta-analysis was possible. Hearing One study found that more children may return to normal hearing by two months (resolution of the air-bone gap) after receiving antibiotics as compared with placebo, but the evidence is very uncertain (Peto odds ratio (OR) 9.59, 95% confidence interval (CI) 3.51 to 26.18; 20/49 children who received antibiotics returned to normal hearing versus 0/37 who received placebo; 1 study, 86 participants; very low-certainty evidence). Disease-specific quality of life No studies assessed this outcome. Presence/persistence of OME At 6 to 12 months of follow-up, the use of antibiotics compared with placebo may slightly reduce the number of children with persistent OME, but the confidence intervals were wide, and the evidence is very uncertain (risk ratio (RR) 0.89, 95% CI 0.68 to 1.17; 48% versus 54%; number needed to treat (NNT) 17; 2 studies, 324 participants; very low-certainty evidence). Adverse event: anaphylaxis No studies provided specific data on anaphylaxis. Three of the included studies (448 children) did report adverse events in sufficient detail to assume that no anaphylactic reactions occurred, but the evidence is very uncertain (very low-certainty evidence). Antibiotics versus no treatment We included eight studies for this comparison, but very limited meta-analysis was possible. Hearing One study found that the use of antibiotics compared to no treatment may result in little to no difference in final hearing threshold at three months (mean difference (MD) -5.38 dB HL, 95% CI -9.12 to -1.64; 1 study, 73 participants; low-certainty evidence). The only data identified on the return to normal hearing were reported at 10 days of follow-up, which we considered to be too short to accurately reflect the efficacy of antibiotics. Disease-specific quality of life No studies assessed this outcome. Presence/persistence of OME Antibiotics may reduce the proportion of children who have persistent OME at up to three months of follow-up, when compared with no treatment (RR 0.64, 95% CI 0.50 to 0.80; 6 studies, 542 participants; low-certainty evidence). Adverse event: anaphylaxis No studies provided specific data on anaphylaxis. Two of the included studies (180 children) did report adverse events in sufficient detail to assume that no anaphylactic reactions occurred, but the evidence is very uncertain (very low-certainty evidence). AUTHORS' CONCLUSIONS: The evidence for the use of antibiotics for OME is of low to very low certainty. Although the use of antibiotics compared to no treatment may have a slight beneficial effect on the resolution of OME at up to three months, the overall impact on hearing is very uncertain. The long-term effects of antibiotics are unclear and few of the studies included in this review reported on potential harms. These important endpoints should be considered when weighing up the potential short- and long-term benefits and harms of antibiotic treatment in a condition with a high spontaneous resolution rate